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

Abstract

The present disclosure relates to a wireless communication system, a wireless communication method, a wireless communication device, and a wireless communication program. This wireless communication system is provided with a transmission device having a control unit and an MCS determination unit. The control unit is configured to execute: processing for setting a plurality of packets in a simultaneous transmission packet group; processing for temporarily determining an MCS for each packet set in the simultaneous transmission packet group; and processing for transmitting each packet for which the MCS has been temporarily determined to a different MCS determination unit. The MCS determination unit is configured to execute: processing for determining the frame length of each packet on the basis of the temporarily determined MCS and the packet length of each received packet; processing for sharing information on the determined frame length with another MCS determination unit; processing for selecting the longest packet from the simultaneous transmission packet group; and processing for changing the MCS for each packet other than the longest packet set in the simultaneous transmission packet group. The MCS is changed by lowering the MCS within a range in which the frame length of the corresponding packet after the MCS change does not exceed the frame length of the longest packet.

Description

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

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

[0002] In NSTR (Nonsimultaneous transmit and receive) devices, in order to suppress signal interference between links, it is necessary to unify the length of the PPDU (PLCP Protocol Data Unit) of each link. To unify the PPDU length, an optional padding section (PAD) is inserted at the end of a PPDU that is shorter than the PPDU of another link.

[0003] IEEE P802.11be / D4.0, PPDU end time alignment on an NSTR link pair, 35.3.16.5, July 2023

[0004] However, since the PAD is a part that does not contribute to data transmission, inserting the PAD poses a problem of reduced communication and power efficiency.

[0005] In order to solve the above-mentioned problems, the first object of the present disclosure is to provide a wireless communication system that can improve communication and power efficiency in a wireless communication method that unifies frame lengths by inserting PADs.

[0006] A first aspect of the present disclosure is a wireless communication system including a transmitting device having a control unit and an MCS determination unit, wherein the control unit is configured to execute a process of setting a plurality of packets as a simultaneously transmitted packet group, a process of tentatively determining an MCS for each packet set in the simultaneously transmitted packet group, and a process of transmitting each packet for which an MCS has been tentatively determined to a different MCS determination unit, and the MCS determination unit is configured to execute a process of determining a frame length of each packet based on the packet length of each received packet and the tentatively determined MCS, a process of sharing information about the determined frame length with other MCS determination units, a process of selecting the longest packet from the simultaneously transmitted packet group, and a process of changing the MCS for each packet other than the longest packet set in the simultaneously transmitted packet group, and the wireless communication system is preferably configured to change the MCS by lowering the MCS within a range such that the frame length of the corresponding packet after the MCS change does not exceed the frame length of the longest packet.

[0007] Furthermore, a second aspect of the present disclosure is preferably a wireless communication method configured to perform the following: setting a plurality of packets in a simultaneous transmission packet group; tentatively determining an MCS for each packet set in the simultaneous transmission packet group; transmitting each packet for which an MCS has been tentatively determined to a different MCS determination unit; determining a frame length for each packet based on the packet length of each received packet and the tentatively determined MCS; sharing information about the determined frame lengths; selecting the longest packet from the simultaneous transmission packet group; and changing the MCS for each packet other than the longest packet set in the simultaneous transmission packet group, wherein the MCS change is performed by lowering the MCS within a range in which the frame length of the corresponding packet after the MCS change does not exceed the frame length of the longest packet.

[0008] Furthermore, a third aspect of the present disclosure is preferably a wireless communication device including a control unit and an MCS determination unit, wherein the control unit is configured to execute a process of setting a plurality of packets in a simultaneous transmission packet group, a process of tentatively determining an MCS for each packet set in the simultaneous transmission packet group, and a process of transmitting each packet for which an MCS has been tentatively determined to a different MCS determination unit, and the MCS determination unit is configured to execute a process of determining a frame length of each packet based on the packet length of each received packet and the tentatively determined MCS, a process of sharing information about the determined frame length with other MCS determination units, a process of selecting the longest packet from the simultaneous transmission packet group, and a process of changing the MCS for each packet other than the longest packet set in the simultaneous transmission packet group, and the MCS change is performed by lowering the MCS within a range in which the frame length of the corresponding packet after the MCS change does not exceed the frame length of the longest packet.

[0009] Furthermore, a fourth aspect of the present disclosure is preferably a wireless communication program to be executed by a wireless communication device that has a processor and a memory and is connected to a plurality of APs, the wireless communication program being stored in the memory and computer-readable, and including a program that causes the processor to execute the following processes: setting a plurality of packets into a simultaneous transmission packet group; tentatively determining an MCS for each packet set in the simultaneous transmission packet group; transmitting each packet for which an MCS has been provisionally determined to a different MCS determination unit; determining a frame length for each packet based on the packet length of each received packet and the provisionally determined MCS; sharing information about the determined frame lengths; selecting the longest packet from the simultaneous transmission packet group; and changing the MCS for each packet other than the longest packet set in the simultaneous transmission packet group.

[0010] According to the first to fourth aspects of the present disclosure, it is possible to improve communication and power efficiency in a wireless communication system in which PADs are inserted to unify frame lengths.

[0011] Fig. 1 is a first diagram showing frame lengths before and after an MCS change according to embodiment 1 of the present disclosure. Fig. 2 is a second diagram showing frame lengths before and after an MCS change according to embodiment 1 of the present disclosure. Fig. 3 is a diagram showing a configuration example of a transmission device according to embodiment 1 of the present disclosure. Fig. 4 is a diagram showing a hardware configuration example of a transmission device according to embodiment 1 of the present disclosure.

[0012] 1 is a first diagram showing frame lengths before and after an MCS change according to a first embodiment of the present disclosure. Here, a method for unifying the frame lengths of two packets transmitted simultaneously in an NSTR terminal will be described. Hereinafter, the packets transmitted simultaneously will be referred to as a simultaneous transmission packet group, and the frame length at the time of transmission will be simply referred to as the frame length.

[0013] The upper diagram in Figure 1 is a first diagram showing the frame lengths of two packets before the MCS is changed. Hereinafter, the packet transmitted using link 1 will be referred to as packet 1, and the packet transmitted using link 2 will be referred to as packet 2.

[0014] The frame length of packet 1 is indicated by PPDU 10. The frame length of packet 2 is indicated by PPDU 10a. PPDU 10a is the PPDU when packet 2 is processed with a higher MCS than PPDU 10b, which will be described later.

[0015] As shown in the figure, the frame length of packet 1 is longer than the frame length of packet 2. Therefore, if the MCS of packet 2 is not changed, the frame length of packet 2 can be unified with that of packet 1 by inserting PAD 20a at the end.

[0016] The bottom diagram in Figure 1 is a second diagram showing the frame lengths of two packets after the MCS has been changed. The frame length of packet 1 is indicated by PPDU 10. The frame length of packet 2 is indicated by PPDU 10b. PPDU 10b is the PPDU when packet 2 is processed with a lower MCS than PPDU 10a.

[0017] As shown in the figure, the frame length of packet 1 is unified with the frame length of packet 2. This is because the PPDU indicating the frame length of packet 2 is changed to PPDU 10b by changing the MCS used to process packet 2. As a result, packet 2 can have the same frame length as packet 1 without inserting a PAD at the end.

[0018] In this case, the MCS is changed by lowering the MCS of a specific packet so that the frame length of the packet after the MCS change does not exceed the frame length of the packet with the longest frame length in the group of simultaneously transmitted packets. Hereinafter, the packet with the longest frame length in the group of simultaneously transmitted packets will be simply referred to as the longest packet. In this embodiment, the MCS is changed by lowering the MCS of packet 2 so that the frame length of packet 2 after the MCS change does not exceed the frame length of packet 1, which is the longest packet.

[0019] 2 is a second diagram illustrating frame lengths before and after changing the MCS according to the first embodiment of the present disclosure. This diagram illustrates a case where the frame lengths of a group of simultaneously transmitted packets cannot be unified even when the MCS of packets other than the longest packet is lowered.

[0020] The upper diagram of Fig. 2 is a second diagram showing the frame lengths of two packets before the MCS is changed. The upper diagram of Fig. 2 is the same as the upper diagram of Fig. 1, so a description thereof will be omitted.

[0021] The bottom diagram in Figure 2 is a second diagram showing the frame lengths of the two packets after the MCS has been changed. In the bottom diagram in Figure 2, by changing the MCS of packet 2, the PPDU indicating the frame length of packet 2 is changed to PPDU 10c. As a result, by inserting PAD 20b at the end of packet 2, the frame length of packet 2 can be unified with that of packet 1.

[0022] In this case, the MCS is changed by lowering the MCS of a specific packet so that the frame length of the corresponding packet after the MCS change does not exceed the frame length of the longest packet. In addition, the MCS is changed by lowering the MCS of the specific packet so that the PAD after the MCS change is minimized. The MCS that minimizes the PAD may be determined by, for example, comparing the PPDU lengths of all MCSs available for the NSTR terminal and selecting the MCS that minimizes the PAD.

[0023] Furthermore, when there are multiple specific packets for which the MCS needs to be changed, the MCS change according to the present disclosure may be performed by assigning a lower MCS and shorter data length to packets transmitted in descending order of the packet error rate of the link used for transmitting the packets. As a result, packets transmitted using links with higher packet error rates will be transmitted using a lower MCS and shorter data length. In other words, the communication and power efficiency of the entire system can be improved.

[0024] The effect of changing the MCS will now be described. As described above, by changing the MCS of packet 2 to a lower one, the frame length of packet 2 itself can be increased. As a result, the PAD, which is a portion that does not contribute to data transmission, can be shortened, thereby improving communication and power efficiency.

[0025] Furthermore, by lowering the MCS of packet 2, the durability of wireless communication is improved. For example, by lowering the MCS, packet transmission errors can be reduced, resulting in fewer repeated communications. As a result, the communication and power efficiency of the entire system can be improved.

[0026] 3 is a diagram illustrating an example of the configuration of a transmission device according to the first embodiment of the present disclosure, in which the U-MAC unit 2 and the L-MAC unit 4 included in the transmission device 10 are shown enlarged.

[0027] The transmitting device 10 shown here is a transmitting device that can dynamically set different MCS or the number of streams for each link, and has, for example, an EMLMR (Enhanced Multi Link Multi Radio) mechanism.

[0028] The transmitting device 10 includes a U-MAC unit 2. The U-MAC unit 2 includes a transmission buffer 22. The transmission buffer 22 stores packets received from an upper layer.

[0029] The transmission buffer 22 transmits the stored packets to the control unit 24. The control unit 24 sets a plurality of packets from among the received packets as a group of packets to be simultaneously transmitted.

[0030] Next, the control unit 24 provisionally determines an MCS for each packet set in the simultaneously transmitted packet group. Furthermore, the control unit 24 transmits each packet set in the simultaneously transmitted packet group to a different MCS determination unit in order to allocate each packet to a different link.

[0031] The number of MCS determination units provided is the same as the number of links available to the transmitting device 10, and each MCS determination unit performs processing to transmit packets using a different link.

[0032] Here, for example, three packets, packets A, B, and C, are set as a group of packets to be transmitted simultaneously, and each packet is transmitted to the MCS determination units 26a, 26b, and 26c, respectively.

[0033] The control unit 24 may rearrange the received packets in descending order of payload length and set packets that are close to each other as a group of packets to be simultaneously transmitted. As a result, packets with small differences in payload length can be set as a group of packets to be simultaneously transmitted. In other words, the difference in frame length can be reduced before the MCS is changed, thereby shortening the PAD.

[0034] The MCS determiners 26a, 26b, and 26c determine the frame length of each packet based on the packet length of the received packet and the provisionally determined MCS. The MCS determiners 26a, 26b, and 26c then share information about the frame lengths of each packet. The MCS determiners 26a, 26b, and 26c then select the packet with the longest frame length from the group of simultaneously transmitted packets. Hereinafter, this packet will be referred to as the longest packet. Hereinafter, it is assumed that packet A is selected as the longest packet.

[0035] Next, the MCS determiners 26 a, 26 b, and 26 c change the MCS of each packet other than the longest packet set in the simultaneously transmitted packet group by lowering the MCS to a level that does not cause the frame length of the corresponding packet after the MCS change to exceed the frame length of the longest packet.

[0036] Here, it is assumed that the MCS determination unit 26b changes the MCS of packet B, and the MCS determination unit 26c changes the MCS of packet C. This MCS change is performed by lowering the MCS within a range that does not exceed the frame length of packet A.

[0037] The MCS determiner 26a transmits the allocated packets and information on the MCS determined for those packets to the L-MAC 4a. Similarly, the MCS determiner 26b transmits the allocated packets and information on the MCS determined for those packets to the L-MAC 4b. Similarly, the MCS determiner 26c transmits the allocated packets and information on the MCS determined for those packets to the L-MAC 4c.

[0038] If the packet has the longest frame length among all packets to be simultaneously transmitted, the MCS determined for that packet is the MCS provisionally determined by the control unit 24. If the packet is any packet other than the packet with the longest frame length among all packets to be simultaneously transmitted, the MCS determined for that packet is the MCS changed by the corresponding MCS determination unit.

[0039] The L-MACs 4a, 4b, and 4c process the received packets based on the received MCS information. Then, the L-MACs 4a, 4b, and 4c transmit the processed packets to a lower layer. The packets transmitted to the lower layer are then transmitted to other wireless devices.

[0040] Furthermore, the L-MACs 4a, 4b, and 4c transmit feedback requesting a change of the MCS as needed to the control unit 24. Feedback is required, for example, when it becomes necessary to change the MCS due to a deterioration in the S / N ratio of the link used for transmitting packets.

[0041] 4 is a diagram illustrating an example of a hardware configuration of a transmission device according to the first embodiment of the present disclosure. Each function of the transmission device 10 may be partially or entirely configured by hardware such as a programmable logic device (PLD) or a field programmable gate array (FPGA), or may be configured as a program executed by a processor such as a CPU.

[0042] For example, the transmitting device 10 can be realized using a computer and a program, and the program can be recorded on a storage medium or provided via a network.

[0043] 4, the transmitting device 10 has an input unit 200, an output unit 201, a communication unit 202, a CPU 203, a memory 204, and an HDD 205 connected via a bus 206, and functions as a computer. The transmitting device 10 is also capable of inputting and outputting data to and from a computer-readable storage medium 207.

[0044] The input unit 200 is, for example, a keyboard and a mouse, etc. The output unit 201 is, for example, a display device such as a display.

[0045] The communication unit 202 is, for example, a communication interface that communicates with a wireless device to be controlled.

[0046] The CPU 203 controls each component of the transmitting device 10 and performs predetermined processing, etc. The memory 204 and HDD 205 store data, etc.

[0047] The storage medium 207 is capable of storing programs and the like that cause the transmitting device 10 to execute the functions of the transmitting device 10. Note that the architecture that configures the transmitting device 10 is not limited to the example shown in FIG.

[0048] As described above, according to the present disclosure, the MCS is changed for each packet other than the packet with the longest frame length among all packets to be simultaneously transmitted, thereby improving communication and power efficiency.

[0049] Although the present disclosure has described a method for unifying frame lengths in NSTR terminals, the present disclosure is not limited to this. For example, the present disclosure may be applied to wireless communication systems other than NSTR that unify frame lengths by inserting PAD.

[0050] In addition, although the present disclosure describes a mode in which a specific frame length is unified with the frame length of the longest packet by lowering the MCS, the present disclosure is not limited to this. For example, a method of unifying a specific frame length with the frame length of the longest packet by lowering the coding rate or adding an error correction code may be applied to the present disclosure.

[0051] Furthermore, in the present disclosure, the transmitting device 10 is a wireless communication device, but the present disclosure is not limited to this, and the transmitting device 10 may be any communication device that can communicate with other devices.

[0052] 10 Transmitting device 24 Control unit 26a Determination unit 26a MCS determination unit 26b Determination unit 26b MCS determination unit 26c MCS determination unit

Claims

1. A wireless communication system comprising a transmitting device having a control unit and an MCS determination unit, wherein the control unit is configured to perform the following processes: setting a plurality of packets into a simultaneously transmitted packet group; tentatively determining an MCS for each packet set in the simultaneously transmitted packet group; and transmitting each packet for which an MCS has been tentatively determined to a different MCS determination unit, wherein the MCS determination unit is configured to perform the following processes: determining the frame length of each packet based on the packet length of each received packet and the tentatively determined MCS; sharing information on the determined frame length with other MCS determination units; selecting the longest packet from the simultaneously transmitted packet group; and changing the MCS for each packet other than the longest packet set in the simultaneously transmitted packet group, wherein the MCS is changed by lowering the MCS within a range such that the frame length of the corresponding packet after the MCS change does not exceed the frame length of the longest packet.

2. A wireless communication method configured to perform the following: setting a plurality of packets as a simultaneous transmission packet group; tentatively determining an MCS for each packet set in the simultaneous transmission packet group; transmitting each packet with its tentatively determined MCS to a different MCS determination unit; determining the frame length of each packet based on the packet length of each received packet and the tentatively determined MCS; sharing information on the determined frame lengths; selecting the longest packet from the simultaneous transmission packet group; and changing the MCS for each packet other than the longest packet set in the simultaneous transmission packet group, wherein the change in MCS is performed by lowering the MCS within a range such that the frame length of the corresponding packet after the MCS change does not exceed the frame length of the longest packet.

3. A wireless communication device comprising a control unit and an MCS determination unit, wherein the control unit is configured to perform the following processes: setting a plurality of packets into a simultaneous transmission packet group; tentatively determining an MCS for each packet set into the simultaneous transmission packet group; and transmitting each packet for which an MCS has been tentatively determined to a different MCS determination unit; and the MCS determination unit is configured to perform the following processes: determining the frame length of each packet based on the packet length of each received packet and the tentatively determined MCS; sharing information on the determined frame length with other MCS determination units; selecting the longest packet from the simultaneous transmission packet group; and changing the MCS for each packet other than the longest packet set into the simultaneous transmission packet group, and the change in MCS is performed by lowering the MCS within a range such that the frame length of the corresponding packet after the MCS change does not exceed the frame length of the longest packet.

4. A wireless communication program to be executed by a wireless communication device having a processor and memory and connected to multiple APs, the program being stored in the memory and computer-readable, and including programs for causing the processor to perform the following: setting multiple packets into a simultaneous transmission packet group; tentatively determining an MCS for each packet set in the simultaneous transmission packet group; transmitting each packet with a tentatively determined MCS to a different MCS determination unit; determining the frame length of each packet based on the packet length of each received packet and the tentatively determined MCS; sharing information on the determined frame lengths; selecting the longest packet from the simultaneous transmission packet group; and changing the MCS for each packet other than the longest packet set in the simultaneous transmission packet group.

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