WO2025046801A1 - Wireless communication system, wireless communication device, wireless communication method, and wireless communication program - Google Patents

Abstract

The present disclosure relates to a wireless communication system, a wireless communication device, a wireless communication method, and a wireless communication program. This wireless communication system is provided with an AP capable of performing wireless communication using a plurality of links. The AP is configured to execute: a process for acquiring the number of neighboring APs for each available channel; a process for creating an index that ranks the available channels in ascending order of number of neighboring APs; a process for checking whether the number of neighboring APs of each channel is zero in ascending order of rank in the index; a process for assigning a channel to an operational link of the AP if the channel has zero neighboring AP; a process for assigning the channel having the smallest rank to the operational link of the AP if there is no channel having zero neighboring AP and there is no channel assigned to the operational link of the AP; and a process for performing wireless communication using the link assigned with the channel.

Description

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

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

Non-Patent Document 1 discloses the LCCS (Least Congested Channel Selection) method, which is a channel allocation method used by conventional SLDs (Single Link Devices) for communication entities. In the LCCS method, in the first step, a channel with less contention is preferentially assigned to a randomly selected access point (AP). Then, in the second step, a channel with less contention is preferentially assigned to a randomly selected AP different from the first step.

When the above-mentioned LCCS method is extended to a communication entity such as an MLD (Multi Link Device), each of the multiple links used by the MLD is assigned the channel with the least interference. In other words, a channel is assigned to all of the links used by the MLD. Hereinafter, this method will be referred to as the extended LCCS method.

The extended LCCS method is the optimal allocation method when there is no possibility that the corresponding communication entity will interfere with other communication entities. First, because it allocates channels to all links, it is possible to expect an increase in communication volume in proportion to the number of links. In addition, even if all links are communicating, there is no interference with the communication of other communication entities, so there is no problem of a deterioration in the communication characteristics of the entire system.

Arunesh Mishra, Suman Banerjee, William Arbaugh, “Weighted coloring based channel assignment for WLANs”, ACM SIGMOBILE Mobile Computing and Communications Review, July 2005, Volume 9, Issue 3, pp 19-31

However, when the above-mentioned extended LCCS method is used in a communication entity that interferes with other communication entities, such as a wireless LAN in a dense environment, there is a problem that the communication characteristics of the entire system are degraded.

In order to solve the above-mentioned problems, the first objective of this disclosure is to provide a wireless communication system that can maximize the communication characteristics of the entire system by suppressing interference with the communications of other communication entities.

A second object of the present disclosure is to provide a wireless communication device that can maximize the communication characteristics of the entire system by suppressing interference with the communications of other communication entities.

A third object of the present disclosure is to provide a wireless communication method that can maximize the communication characteristics of the entire system by suppressing interference with the communications of other communication entities.

Fourthly, the present disclosure has the objective of providing a wireless communication program that can maximize the communication characteristics of the entire system by suppressing interference with the communications of other communication entities.

The first aspect of the present disclosure is a wireless communication system including an AP capable of performing wireless communication using multiple links, in which the AP is configured to perform the following processes: acquiring the number of neighboring APs for each available channel; creating an index that ranks the available channels in ascending order of the number of neighboring APs; checking, in ascending order of rank in the index, whether the number of neighboring APs of the channel is zero; if a channel with a number of neighboring APs of zero exists, assigning the channel to the link used by the AP; if there is no channel with a number of neighboring APs of zero and no channel has been assigned to the link used by the AP, assigning the channel with the lowest rank to the link used by the AP; and performing wireless communication using the link to which the channel has been assigned.

A second aspect of the present disclosure is a wireless communication device capable of performing wireless communication using multiple links, and is preferably configured to perform the following processes: acquiring the number of neighboring APs for each available channel; creating an index that ranks the available channels in ascending order of the number of neighboring APs; checking whether the number of neighboring APs for a channel is zero, in ascending order of rank in the index; assigning the channel to the link used by the AP if a channel with zero number of neighboring APs exists; assigning the channel with the lowest rank to the link used by the AP if there is no channel with zero number of neighboring APs and if there is no channel assigned to the link used by the AP; and performing wireless communication using the link to which the channel has been assigned.

A third aspect of the present disclosure is a wireless communication method implemented by a wireless communication device capable of performing wireless communication using multiple links, which preferably includes the steps of: acquiring the number of neighboring APs for each available channel; creating an index that ranks the available channels in ascending order of the number of neighboring APs; checking whether the number of neighboring APs for a channel is zero, beginning with the lowest ranking in the index; assigning the channel to the link used by the AP if a channel with a number of neighboring APs is zero; and assigning the channel with the lowest ranking to the link used by the AP if there is no channel with a number of neighboring APs zero and no channel has been assigned to the link used by the AP; and performing wireless communication using the link to which the channel has been assigned.

A fourth aspect of the present disclosure is a wireless communication program that can perform wireless communication using multiple links and is executed by a wireless communication device having a processor and a memory, the wireless communication program being stored in the memory and computer-readable, and preferably including a program that causes the processor to perform the following processes: acquiring the number of neighboring APs for each available channel; creating an index that ranks the available channels in ascending order of the number of neighboring APs; checking whether the number of neighboring APs for a channel in ascending order of rank in the index is zero; if a channel with zero number of neighboring APs exists, assigning the channel to the link used by the AP; if there is no channel with zero number of neighboring APs and no channel assigned to the link used by the AP, assigning the channel with the lowest rank to the link used by the AP; and performing wireless communication using the link to which the channel has been assigned.

According to the first to fourth aspects of the present disclosure, it is possible to maximize the communication characteristics of the entire system by suppressing interference with the communications of other communication entities.

1 is a diagram illustrating a configuration of a wireless communication system according to a first embodiment of the present disclosure. FIG. 2 is a first diagram showing a hardware configuration of an AP according to a first embodiment of the present disclosure. FIG. 2 is a second diagram showing the hardware configuration of the AP according to the first embodiment of the present disclosure. 4 is a flowchart showing a channel allocation process according to the first embodiment of the present disclosure. 11 is a chart showing classification of selection criteria C according to the first embodiment of the present disclosure. 11 is a flowchart showing a process when the channel allocation criterion according to the first embodiment of the present disclosure is a reference AAL. 11 is a flowchart showing a process when the channel allocation criterion according to the first embodiment of the present disclosure is a reference OSL. 11 is a flowchart showing a process when a channel allocation criterion according to the first embodiment of the present disclosure is a criterion FLN. FIG. 2 is a diagram showing an overview of computer simulation conditions according to the first embodiment of the present disclosure. 1 is a graph showing a relationship between the number of BSSs and average throughput in a computer simulation according to the first embodiment of the present disclosure. 1 is a graph showing a relationship between the number of BSSs and fairness in a simulation according to the first embodiment of the present disclosure. 1 is a graph showing a relationship between the number of BSSs and the minimum throughput in a simulation according to the first embodiment of the present disclosure.

First embodiment
[Configuration of wireless communication system according to embodiment 1 of the present disclosure]
1 is a diagram showing a configuration of a wireless communication system according to a first embodiment of the present disclosure. Here, a wireless communication system 100 according to the first embodiment of the present disclosure is described, which includes five BSSs (Basic Service Sets). The wireless communication system 100 is, for example, a wireless communication system that uses 802.11be as a communication standard.

The wireless communication system 100 includes a BSS2a. The BSS2a includes an AP4a. The AP4a is an MLD that can perform wireless communication using multiple links. Here, the AP4a performs wireless communication using three links. The AP4a performs a channel allocation process, which will be described later, to assign a channel to at least one of the three links and perform wireless communication.

This AP4a performs wireless communication with the wireless communication terminal 6. Here, the BSS2a is shown to have three wireless communication terminals 6 using three links.

The wireless communication system 100 also includes BSSs 2b to 2e. Like BSS 2a, BSSs 2b to 2e also include APs 4b to 4e. Like AP 4a, APs 4b to 4e perform wireless communication with three wireless communication terminals 6.

FIG. 2 is a first diagram showing the hardware configuration of an AP according to the first embodiment of the present disclosure. FIG. 2 shows a configuration in which the functions of the wireless communication device according to the first embodiment of the present disclosure are realized by hardware.

AP4a-1 is equipped with a receiving device 42. The receiving device 42 receives information transmitted from other wireless devices and transmits it to a processing circuit 45. The processing circuit 45 is a dedicated hardware circuit for performing the channel allocation process described below. The transmitted information is information necessary for the channel allocation process described below, such as the number of neighboring APs described below.

When the channel allocation is determined by the processing of the processing circuit 45, the information necessary for the channel allocation is transmitted to the transmitting device 48. The transmitting device 48 performs wireless communication with other wireless communication devices using the channel allocation based on the transmitted information. In other words, the AP 4a-1 can realize functions unique to this embodiment by the processing circuit 45 executing the processing.

FIG. 3 is a second diagram showing the hardware configuration of an AP according to the first embodiment of the present disclosure. FIG. 3 shows a configuration in which the functions of the wireless communication device according to the first embodiment of the present disclosure are realized by software.

AP4a-2 has a processor 44 and a memory 46 instead of the processing circuit 45 in FIG. 2. The memory 46 stores a wireless communication program executed by the processor 44. The processor 44 executes the wireless communication program, allowing AP4a to realize functions unique to this embodiment.

In other words, the functions of AP4a-2 can be realized by a computer and the program. The program can also be recorded on a recording medium or provided via a network.

[Channel allocation process performed by the AP according to the first embodiment of the present disclosure]
4 is a flowchart showing a channel allocation process according to the first embodiment of the present disclosure. First, in step 100, AP selection is performed. This step is a step of selecting an AP that performs channel allocation processing from among a plurality of APs included in the wireless communication system. This AP selection may be performed based on, for example, a selection criterion C described later.

An example of an entity that performs step 100 is a network controller. This network controller is connected to all APs in the wireless communication system 100 and is capable of sending and receiving information with each AP. In other words, if a network controller is the entity that performs step 100, the wireless communication system 100 needs to include a network controller in addition to the configuration in FIG. 1.

AP selection can be performed, for example, by the network controller selecting an AP that will perform channel allocation processing and notifying the corresponding AP of the selection result. Upon receiving the notification, the selected AP performs channel allocation processing. In this example, the network controller does not need to know the location information of all APs.

If the network controller knows the location information of all APs, it may calculate the order of AP selection in advance so that the channel allocation process can be performed most efficiently. Furthermore, the network controller may perform the channel allocation process described below in addition to AP selection. In this case, the network controller notifies the corresponding AP of the AP selection results and the channel allocation results.

Step 100 may be omitted if the AP performs channel allocation processing independently of other APs. In this case, there are four examples of the channel allocation processing method.

First, an example of a method is that the AP that performed the channel allocation process performs the channel allocation process again after a fixed time or a randomly determined time has elapsed. Second, an example of a method is that the AP that performed the channel allocation process performs the channel allocation process again, triggered by the "time" that was set at the time of purchase.

A third example is a method in which an AP that has performed channel allocation processing performs channel allocation processing again, triggered by a "change in the number of neighboring APs." Neighboring APs are the number of APs that compete with the selected AP, and are counted when the distance between APs is equal to or less than the neighboring distance. One example of a case in which a "change in the number of neighboring APs" occurs is when a neighboring AP changes the channel it uses.

Fourthly, an example of a method is one in which an AP that has performed a channel allocation process performs the channel allocation process again, triggered by "information obtained from an adjacent AP." For example, the channel allocation process may be performed again after a fixed time or a randomly determined time has elapsed since the AP received a notification that the adjacent AP had performed the channel allocation process.

In the fourth example, an AP that does not have a neighboring AP cannot receive the triggering notification. However, in this case, the channel allocation process performed by the AP in this disclosure allows all available channels to be allocated, so no problem occurs. The channel allocation process will be described in detail later.

In the first to fourth examples, there are three examples of conditions for an AP to end the channel allocation process. The first example is a method in which the channel allocation process ends after a certain amount of time has elapsed since the initial channel allocation process. The certain amount of time may be, for example, a time that was set when the AP was purchased. The time that is set here may be determined, for example, by estimating, using a simulation, the time it takes for all APs in the wireless communication system 100 to complete the channel allocation process.

Secondly, there can be mentioned a method of terminating the channel allocation process when there is no "change in the number of neighboring APs" even when the channel allocation process is performed. Note that when the AP is connected to a network controller, the AP may notify the network controller that there will be no "change in the number of neighboring APs". In this case, the network controller may notify at least one of the connected APs to terminate the channel allocation process.

Thirdly, when the AP is connected to a network controller, one example of a method is to end the channel allocation process when a notification is received from the network controller. First, the AP notifies the network controller that it has performed the channel allocation process. The network controller notifies each AP to end the channel allocation process, for example, when each AP has performed the channel allocation process a certain number of times. The AP may end the channel allocation process when it receives this notification.

Next, in step 102, an allocation process is carried out. In this allocation process, the AP selected in the previous step determines the content of the channel allocation based on the selected channel allocation criteria.

There are three examples of channel allocation criteria used here. The first channel allocation criterion is the standard AAL (Always All Links). With the standard AAL, first, from the available channels, channels with a small number of adjacent APs are selected for the required number of links. The selected channels are then assigned to all links to be used.

The second channel allocation criterion is the reference OSL (Occasionally Selected Links). With reference OSL, if there is a channel with zero neighboring APs, that channel is assigned to the link that will be used. Also, if there is no channel with zero neighboring APs, the channel with the fewest neighboring APs is selected and that channel is assigned to the link that will be used. In other words, with reference OSL, channels are not necessarily assigned to all links that an AP can use.

The third channel allocation criterion is the reference FLN (Fixed Link Number). Here, FLN is the number of links used by the selected AP, and is a value that can be freely set as long as it is equal to or less than the number of links available to the AP. With the reference FLN, the available channels are first ranked in order of the number of adjacent APs with the least number. Then, the channel with the FLN number with the least number of adjacent APs is selected and assigned to the link to be used.

The first to third channel allocation criteria select channels to be assigned to the link to be used based on the number of neighboring APs. If multiple channels with the same number of neighboring APs are detected, the required number of channels may be randomly selected from the multiple channels.

There are two examples of methods by which the AP selects the channel allocation criterion in step 102. The first method is to compare the estimated values of communication characteristics according to the channel allocation criteria in real time and select the optimal channel allocation criterion. For example, first, the communication quality when all selectable channel allocation criteria are selected is simulated. Then, by comparing the simulation results, the channel allocation criterion that can maximize the communication characteristics of the entire system is selected. This method is particularly useful when the communication characteristics of the entire system can be simulated in real time.

The second method is to select the channel allocation criteria in advance based on the factors that the entire system prioritizes in terms of communication characteristics. Based on the simulation results described below, the desired effect can be achieved by always selecting the reference AAL when prioritizing total throughput, and the reference OSL when prioritizing maximizing minimum throughput or fairness. This method is particularly useful when the communication characteristics of the entire system can be simulated in advance.

As described above, the channel allocation criteria selected in the allocation process of step 102 may always be the same, or may be switched depending on the target element in the communication characteristics. For example, by switching the channel allocation criteria depending on the application being applied, it may be possible to improve the communication characteristics of the entire system.

Note that in the allocation process of step 102, the method in which the reference AAL is always selected is hereinafter referred to as the LCCS-AAL method. Similarly, the method in which the reference OSL is always selected is hereinafter referred to as the LCCS-OSL method. Furthermore, the method in which the reference FLN is always selected and the FLN value can be freely set is hereinafter referred to as the LCCS-FLN method.

Next, in step 104, channel allocation is performed. This channel allocation is a process that actually assigns channels to the links used by the AP based on the channel allocation content determined in the previous step.

Next, in step 106, it is confirmed whether to adjust the number of channels. This channel number adjustment is a process of further increasing or decreasing the number of channels to be assigned based on the number of channels assigned in the previous step. If it is to be performed, proceed to step 108. If it is not to be performed, end the channel assignment process.

Next, in step 108, the channel number operation is performed and the channel allocation process is terminated. For example, the number of channels to be allocated is increased and new channels are allocated to links that do not have channels assigned to them. Alternatively, the number of channels to be allocated is decreased and channels that have already been assigned to links are no longer in use. This operation allows fine adjustment of the channel allocation.

The channel allocation process shown in FIG. 4 may be performed in a batch manner or sequentially. Sequential execution is applied, for example, when an AP is added to the wireless communication system 100.

[Advantages of the channel allocation process according to the first embodiment of the present disclosure]
The advantages of the above-mentioned channel allocation process will be explained by comparing it with the conventional channel allocation process. The conventional extended LCCS method allocates channels to all links that an AP can use. Therefore, if an AP using the channel interferes with other APs, it has a problem of degrading the communication characteristics of the entire system.

For example, consider wireless communication system #1 in which AP#1, AP#2, and AP#3 using the extended LCCS method are arranged in a horizontal line. AP#1 and AP#3, located at both ends, can obtain access rights because AP#2 is the only neighboring AP. However, AP#2 cannot obtain access rights because AP#1 and AP#3, which have access rights, are neighboring APs. AP#2 in this case will be referred to as a starving AP hereafter.

Next, consider wireless communication system #2, in which AP#1, AP#2, and AP#3, which use the extended LCCS method, are positioned to form an equilateral triangle. In this case, each of the three APs has two neighboring APs, and can obtain equal access rights.

As described above, when APs constituting a wireless communication system use the extended LCCS method, starving APs may occur depending on the relative positions of the APs. In other words, the occurrence of starving APs that depend on the competing topology may degrade the communication characteristics of the entire system.

On the other hand, in the channel allocation process according to the first embodiment of the present disclosure, channels are not allocated to all links that an AP can use. For example, when the channel allocation criterion is a reference OSL, only channels with zero neighboring APs or channels with the fewest neighboring APs are allocated. Also, when the channel allocation criterion is a reference FLN, only channels with FLN numbers in ascending order of the number of neighboring APs are allocated. This makes it possible to suppress interference with other communication entities, thereby maximizing the communication characteristics of the entire system.

Furthermore, in the channel allocation process according to the first embodiment of the present disclosure, it is also possible to implement the same channel allocation process as the extended LCCS method that has been used conventionally. For example, if the relevant AP does not have an adjacent AP, the same channel allocation process as the extended LCCS method can be implemented by selecting the reference AAL as the channel allocation criterion. In other words, by appropriately selecting the channel allocation criterion from multiple candidates, it is possible to maximize the communication characteristics of the entire system according to the situation.

[Details of Channel Allocation Process According to the First Embodiment of the Present Disclosure]
5 is a chart showing a classification of selection criteria C according to the first embodiment of the present disclosure. Selection criteria C is an example of a criterion for selecting an AP for performing a channel allocation process in step 100 of FIG.

AP selection may be performed, for example, randomly or regularly. When AP selection is performed regularly, it may be performed periodically or based on a trigger. When AP selection is performed periodically, it may be performed, for example, by setting serial numbers for all APs in the wireless communication system and changing the APs to be selected in order of serial numbers every time a certain period of time has passed.

Furthermore, when AP selection is performed regularly and based on a trigger, the calculation result of the estimated throughput may be the trigger, or it may be performed based on other triggers such as time. When the calculation result of the estimated throughput is used as the trigger, for example, the estimated throughput of the simple method may be used, or BoE (Back-of-the-Envelope) may be used. The estimated throughput of the simple method may be calculated using the formula, for example, (channel throughput) / (number of adjacent APs + 1). Note that the calculation result of the estimated throughput is used as a trigger only when the estimated throughput of other APs can be referenced, as in the case of the centralized control method.

FIG. 6 is a flowchart showing the process when the channel allocation criterion according to the first embodiment of the present disclosure is the reference AAL. Note that the steps with the same content in FIGS. 6 to 8 may be omitted or simplified as appropriate.

First, in step 110, AP selection is performed. This AP selection is the same as the AP selection in step 100 in FIG. 4.

Next, in step 112, the channel ch is set to 1. Next, in step 114, N_AP(ch) is obtained. N_AP(ch) is the number of neighboring APs on the channel ch of the selected AP.

Next, in step 116, the channel ch is set to ch+1. Next, in step 118, it is confirmed whether the channel ch is N+1, where N is the number of channels available for use by the selected AP. If it is N+1, the process proceeds to step 120. If it is not N+1, the process returns to step 114. As described above, in steps 112 to 118, the process of acquiring the number of adjacent APs for each channel available for use by the selected AP is performed.

Next, in step 120, [S, Index] is created. Here, [S, Index] is an index that ranks the channels so that N_AP is in ascending order, and the elements of this index are channel numbers. That is, in step 120, a process is performed to create an index that ranks the available channels so that the number of adjacent APs is in ascending order.

Next, in step 122, the channels 1 through link in the index created in step 120 are assigned to the links used by the selected AP. Here, link is the number of links used by the selected AP.

As described above, in the standard AAL, first, from the available channels, channels with a small number of neighboring APs are selected for the required number of links. The selected channels are then assigned to all the links to be used.

FIG. 7 is a flowchart showing the process when the channel allocation criterion according to the first embodiment of the present disclosure is the reference OSL. Steps 110 to 120 are the same as the process in FIG. 6.

Next, in step 126, k is set to 1 and l is set to 0. Here, k is a variable that indicates the ranking in the index created in step 120. Also, l is a variable that indicates the number of links that have been assigned to the selected AP.

Next, in step 128, it is confirmed whether the kth value in the index created in step 120 is zero. In other words, it is confirmed whether the number of neighboring APs in the corresponding channel of the selected AP is zero. If it is zero, proceed to step 130. If it is not zero, proceed to step 134.

Next, in step 130, the kth channel in the index created in step 120 is assigned to the link used by the selected AP, and l is set to l+1. Next, in step 132, it is confirmed whether l is link. As mentioned above, link is the number of links used by the selected AP. If it is link, the process is completed. If it is not link, proceed to step 134.

In step 134, k is set to k+1. Next, in step 136, it is confirmed whether k is N+1, where N is the number of channels available to the selected AP as described above. If it is N+1, proceed to step 138. If it is not N+1, return to step 128.

Next, in step 138, it is confirmed whether l is zero. In other words, it is confirmed whether there are no links assigned to the selected AP. If it is zero, it proceeds to step 140. If it is not zero, the process ends.

Next, in step 140, the first channel in the index created in step 120 is assigned to the link used by the selected AP, and the process ends. The first channel in the index created in step 120 is the channel with the lowest ranking in the index. In other words, in step 140, the channel with the smallest number of corresponding neighboring APs is assigned to the link used by the selected AP.

As described above, in the standard OSL, if there is a channel with zero neighboring APs, that channel is assigned to the link that uses it. Also, if there is no channel with zero neighboring APs, the channel with the fewest neighboring APs is selected and assigned to the link that uses it.

FIG. 8 is a flowchart showing the process when the channel allocation criterion according to the first embodiment of the present disclosure is the reference FLN. Steps 110 to 120 are the same as those in FIG. 6.

Next, in step 142, channels 1 through FLN of the index created in step 120 are assigned to the links used by the selected AP. As mentioned above, FLN is the number of links used by the selected AP, and is a value that can be freely set.

As described above, in the reference FLN, available channels are first ranked in order of the number of neighboring APs. Then, the FLN number of channels is selected in order of the number of neighboring APs, and that channel is assigned to the link to be used.

[Simulation of communication characteristics according to the first embodiment of the present disclosure]
Fig. 9 is a diagram showing an outline of computer simulation conditions according to the first embodiment of the present disclosure. Fig. 9 shows an example in which five BSSs, 2a to 2e, are arranged in an area of 100 m x 100 m. More detailed simulation conditions, including the area and the number of BSSs, are shown in Table 1.

This computer simulation was performed to estimate the changes in communication characteristics that accompany the channel allocation process according to the first embodiment of the present disclosure. In particular, we confirmed the changes in average throughput, fairness, and minimum throughput when using the LCCS-AAL method and the LCCS-OSL method.

In this computer simulation, the median value is plotted for data obtained when AP placement is randomly generated 20 times. 64QAM 5/6 (Quadrature Amplitude Modulation) is used as the MCS (Modulation and Coding Scheme), and 20MHz transmission is assumed. A proprietary simulator was used.

FIG. 10 is a graph showing the relationship between the number of BSSs and the average throughput in a computer simulation according to the first embodiment of the present disclosure. The horizontal axis is the number of BSSs, and the vertical axis is the transmission speed. The dashed line shows the results of the LCCS-AAL method, and the solid line shows the results of the LCCS-OSL method.

The results in Figure 10 show that as the number of BSSs increases, the transmission speed with the LCCS-AAL method increases. In other words, the LCCS-AAL method is superior to the LCCS-OSL method in terms of average throughput.

FIG. 11 is a graph showing the relationship between the number of BSSs and fairness in a simulation according to the first embodiment of the present disclosure. The horizontal axis is the number of BSSs, and the vertical axis is the fairness index. The dashed line shows the results of the LCCS-AAL method, and the solid line shows the results of the LCCS-OSL method.

The results in Figure 11 show that as the number of BSSs increases, the fairness index value for the LCCS-OSL method increases. In other words, the LCCS-OSL method is superior to the LCCS-AAL method in terms of fairness.

FIG. 12 is a graph showing the relationship between the number of BSSs and the minimum throughput in a simulation according to the first embodiment of the present disclosure. The horizontal axis is the number of BSSs, and the vertical axis is the transmission speed. The dashed line shows the results of the LCCS-AAL method, and the solid line shows the results of the LCCS-OSL method.

The results in Figure 12 show that although there are some areas where the transmission speed is faster with the LCCS-AAL method, the transmission speed with the LCCS-OSL method increases as the number of BSSs increases. In other words, the LCCS-OSL method tends to be superior to the LCCS-AAL method in terms of fairness.

The results in Figures 10 to 12 show that the LCCS-AAL method is superior in terms of average throughput, while the LCCS-OSL method is superior in terms of fairness and minimum throughput. The LCCS-OSL method uses a channel allocation criterion that selects a channel in which there are no or few APs competing with the selected AP. This reduces the possibility of generating starving APs, and is therefore believed to improve fairness and minimum throughput in dense environments.

In this computer simulation, we compared the communication quality using the LCCS-AAL method and the LCCS-OSL method, but by also comparing the communication quality using the LCCS-FLN method, it will also be possible to infer the factors that make the LCCS-FLN method useful.

As described above, it can be seen that by selecting different channel allocation criteria, different elements of the communication characteristics can be improved. In other words, by selecting a channel allocation criterion in advance based on which element of the communication characteristics the entire system prioritizes, it is possible to prioritize and improve the desired communication characteristics. Therefore, it is also possible to switch the channel allocation criteria depending on the application to be applied, for example.

4a, 4a-1, 4a-2, 4b, 4c, 4d, 4e AP
44 Processor 46 Memory 100 Wireless communication system

Claims (4)

A wireless communication system including an AP capable of performing wireless communication using a plurality of links,
The AP,
A process of acquiring the number of adjacent APs for each available channel;
A process of creating an index in which the available channels are ranked in ascending order of the number of neighboring APs;
A process of checking whether the number of neighboring APs of the channel is zero, in ascending order of the index;
If there is a channel with zero neighboring APs, the channel is assigned to a link used by the AP;
a process of assigning the channel with the lowest ranking to the link used by the AP when there is no channel with the number of neighboring APs being zero and there is no channel already assigned to the link used by the AP;
and performing wireless communication using a channel assigned link. A wireless communication device capable of performing wireless communication using a plurality of links,
A process of acquiring the number of adjacent APs for each available channel;
A process of creating an index in which the available channels are ranked in ascending order of the number of neighboring APs;
A process of checking whether the number of neighboring APs of the channel is zero, in ascending order of the index;
If there is a channel for which the number of adjacent APs is zero, a process of allocating the channel to a link to be used by the wireless communication device;
a process of assigning the channel with the lowest ranking to the link to be used by the wireless communication device when there is no channel with the number of adjacent APs being zero and there is no channel already assigned to the link to be used by the wireless communication device;
and performing wireless communication using the channel assigned link. A wireless communication method implemented by a wireless communication device capable of performing wireless communication using a plurality of links, comprising:
Obtaining the number of neighboring APs for each available channel;
creating an index in which the available channels are ranked in ascending order of the number of neighboring APs;
checking whether the number of neighboring APs of the channel is zero in ascending order of the index;
If there is a channel in which the number of adjacent APs is zero, assigning the channel to a link to be used by the wireless communication device;
if there is no channel with the number of adjacent APs being zero and there is no channel already assigned to the link in use of the wireless communication device, assigning the channel with the lowest ranking to the link in use of the wireless communication device;
and conducting wireless communication using the channel assigned link. A wireless communication program for causing a wireless communication device having a processor and a memory to execute wireless communication using a plurality of links,
stored in the memory,
It is computer readable;
The processor,
A process of acquiring the number of adjacent APs for each available channel;
A process of creating an index in which the available channels are ranked in ascending order of the number of neighboring APs;
A process of checking whether the number of neighboring APs of the channel is zero, in ascending order of the index;
If there is a channel for which the number of adjacent APs is zero, a process of allocating the channel to a link to be used by the wireless communication device;
a process of assigning the channel with the lowest ranking to the link to be used by the wireless communication device when there is no channel with the number of adjacent APs being zero and there is no channel already assigned to the link to be used by the wireless communication device;
A process of performing wireless communication using a link to which a channel has been assigned; and a process of performing wireless communication using a link to which a channel has been assigned.
A wireless communication program including a program for carrying out the above.

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