This application is a National Stage Entry of PCT/JP2018/027479 filed on Jul. 23, 2018, which claims priority from Japanese Patent Application 2017-227011 filed on Nov. 27, 2017, the contents of all of which are incorporated herein by reference, in their entirety.

TECHNICAL FIELD

The present invention relates to a wireless LAN system, a communication speed upper limit setting method, and a communication speed upper limit setting program. In particular, the present invention relates to a wireless LAN system, a communication speed upper limit setting method, and a communication speed upper limit setting program that are suited to wireless LAN systems for corporations and to an ICT (Information and Communication Technology) for schools/education, where a large number of mobile units (terminals) are operated.

BACKGROUND ART

In recent years, the wireless LAN system has already prevailed as an information infrastructure regardless of corporations or individuals. In particular, by prevalence of mobile terminals, a use case where ten or more terminals are caused to wirelessly belong to a single wireless LAN access point so as to communicate with each other has become not uncommon. More particularly, as for many of the wireless LAN access points for corporations, there are many cases where a large number of mobile units (terminals) are caused to wirelessly belong thereto. Specifically, in recent years, establishment of the ICT environment at schools has been rapidly promoted. There are actual cases where a class utilizing the wireless LAN system is held and more than forty tablet terminals (mobile units) are wirelessly connected to a single wireless LAN access point (a base unit). Specifically, there is a case where a moving image is distributed at once from a teacher's PC (Personal Computer) to students' tablet terminals with use of educational software.

In such a case, when speeds of communication from the wireless LAN access point to the students' tablet terminals vary from each other, such a phenomenon that the moving image cannot be reproduced by a certain one of the students' tablet terminals has occurred, which hinders the progress of the class. Along with rapid development of the establishment of the ICT environment in corporations or at schools, importance of the communication from the wireless LAN access point to the large number of terminals (the mobile units) has been increasing more and more. Functions to enable equitable communication with the large number of terminals (the mobile units), and to equalize the respective speeds of communication with the terminals (the mobile units) to each other have been strongly demanded.

In view of such circumstances, in the “VIDEO CONFERENCE SYSTEM” according to Japanese Unexamined Patent Application Publication No. 2005-260384 as Patent Literature 1, a technology to define and set, in advance on the system side, a fixed upper limit of the respective communication speeds of the terminals (the mobile units) in accordance with the connection number of the terminals to be wirelessly connected as the mobile units to the wireless LAN access point has been proposed.

CITATION LIST

Patent Literature

Japanese Unexamined Patent Application Publication No. 2005-260384

SUMMARY OF INVENTION

Technical Problem

However, even when the technology as disclosed in Patent Literature 1 is employed, problems as follows with the current wireless LAN systems have remained unsolved.

When the plurality of mobile units belong to the single wireless LAN access point (hereinafter, sometimes abbreviated as an ‘AP’) as the base unit, and each of the mobile units communicates at once, the mobile units scramble for a limited bandwidth. As a result, the communication speeds vary from mobile unit to mobile unit. Specifically, a phenomenon that a certain one of the mobile units can satisfactorily communicate, and meanwhile another certain one of the mobile units cannot communicate by failing to secure a communication bandwidth, or cannot communicate at a satisfactory communication speed even if can communicate has occurred. In particular, this tendency is conspicuous in a case where a large number of mobile units present in a certain specific wireless-communication space are caused to belong to the single AP for corporations, schools, or the like.

In addition, as in the technology disclosed in Patent Literature 1, in order to provide the function to limit the speeds of the communication with the mobile units by presetting the communication-speed upper limit on the AP side, the communication-speed upper limit for each of the mobile units needs to be fixedly set in advance on the AP side. Even in such cases, there are no problems as long as the communication-speed upper limit is set in advance in anticipation of the connection to the large number of mobile units, and the anticipated number of mobile units are actually connected.

However, there is a problem that, when the number of the mobile units belonging to the AP sharply decreases, for example, to one afterward, limitation based on the communication-speed upper limit set for the large number of mobile units is imposed on the only one mobile unit, with the result that the mobile unit cannot communicate at a satisfactorily sufficient speed. In other words, the communication-speed upper limit, which is normally set fixedly in advance in anticipation of the connection to the large number, specifically, several tens of mobile units, is a value set on a premise that the several tens of mobile units share the communication bandwidth of the AP. Thus, the communication speed becomes much lower than that in a case where the AP communicates with the only one mobile unit.

As described above, although the current technologies are advantageous to specific cases, setting of the communication-speed upper limit cannot be varied in accordance with variations in environment and in the number of the mobile units. Thus, there are not a few problems for practical use.

(Object of Present Invention)

The present invention has been made in view of the circumstances as described above, and an object of the present invention is to provide a wireless LAN system, a communication speed upper limit setting method, and a communication speed upper limit setting program that enable each mobile unit belonging to a wireless LAN system as a base unit in the wireless LAN system to equitably communicate by setting an appropriate communication-speed upper limit for each of the mobile units in accordance with environments.

Solution to Problem

In order to solve the problems as described above, the wireless LAN system, the communication speed upper limit setting method, and the communication speed upper limit setting program according to the present invention mainly employ the characteristic configurations as follows.

(1) The wireless LAN system according to the present invention includes a wireless LAN access point as a base unit and mobile units. The wireless LAN system is characterized in that

the wireless LAN access point is configured to check the number of belonging mobile units, the mobile units being those present in a wireless communication area of the wireless LAN access point and belonging to the wireless LAN access point,

the wireless LAN access point is configured to perform a shaping operation to calculate and set an upper limit of communication speeds of the belonging mobile units as a common communication-speed upper limit for each of the belonging mobile units when the number of the belonging mobile units is equal to or more than a preset first threshold, and

meanwhile the wireless LAN access point is configured not to perform the shaping operation when the number of the belonging mobile units is less than the preset first threshold.

(2) In addition, according to the present invention, there is provided another wireless LAN system including a wireless LAN access point as a base unit and mobile units. The other wireless LAN system is characterized in that

the wireless LAN access point is configured to check the number of belonging mobile units and the number of communicating mobile units, the belonging mobile units being those present in a wireless communication area of the wireless LAN access point and belonging to the wireless LAN access point, the communicating mobile units being those communicating with the wireless LAN access point among the belonging mobile units,

the wireless LAN access point is configured to perform a shaping operation to calculate and set an upper limit of communication speeds of the communicating mobile units as a common communication-speed upper limit for each of the communicating mobile units when the number of the belonging mobile units is equal to or more than a preset first threshold and the number of the communicating mobile units is equal to or more than a preset second threshold, and

meanwhile the wireless LAN access point is configured not to perform the shaping operation when the number of the belonging mobile units is less than the preset first threshold, or when the number of the communicating mobile units is less than the preset second threshold.

(3) The communication speed upper limit setting method according to the present invention is provided for setting an upper limit of communication speeds of data to be exchanged between a wireless LAN access point as a base unit and mobile units in a wireless LAN system. The communication speed upper limit setting method is characterized by including:

checking, by the wireless LAN access point, the number of belonging mobile units, the mobile units being those present in a wireless communication area of the wireless LAN access point and belonging to the wireless LAN access point; and

performing, by the wireless LAN access point, a shaping step of calculating and setting an upper limit of communication speeds of the belonging mobile units as a common communication-speed upper limit for each of the belonging mobile units when the number of the belonging mobile units is equal to or more than a preset first threshold, or characterized by including:

checking, by the wireless LAN access point, the number of the belonging mobile units, and the number of communicating mobile units as ones of the belonging mobile units, the ones of the belonging mobile units being communicating with the wireless LAN access point; and

performing, by the wireless LAN access point, the shaping step of calculating and setting an upper limit of communication speeds of the communicating mobile units as a common communication-speed upper limit for each of the communicating mobile units when the number of the belonging mobile units is equal to or more than the preset first threshold, and at the same time when the number of the communicating mobile units is equal to or more than a preset second threshold.

(4) The communication speed upper limit setting program according to the present invention is provided for causing a computer to execute a procedure for setting an upper limit of communication speeds of data to be exchanged between a wireless LAN access point as a base unit and mobile units in a wireless LAN system. The communication speed upper limit setting program is characterized by including:

causing the wireless LAN access point to check the number of belonging mobile units, the mobile units being those present in a wireless communication area of the wireless LAN access point and belonging to the wireless LAN access point; and

causing the wireless LAN access point to execute a shaping process for calculating and setting an upper limit of communication speeds of the belonging mobile units as a common communication-speed upper limit for each of the belonging mobile units when the number of the belonging mobile units is equal to or more than a preset first threshold, or characterized by including:

causing the wireless LAN access point to check the number of the belonging mobile units, and the number of communicating mobile units as ones of the belonging mobile units, the ones of the belonging mobile units being communicating with the wireless LAN access point; and

causing the wireless LAN access point to execute the shaping process for calculating and setting an upper limit of communication speeds of the communicating mobile units as a common communication-speed upper limit for each of the communicating mobile units when the number of the belonging mobile units is equal to or more than the preset first threshold, and at the same time when the number of the communicating mobile units is equal to or more than a preset second threshold.

Advantageous Effects of Invention

According to the wireless LAN systems, the communication speed upper limit setting method, and the communication speed upper limit setting program of the present invention, advantages as follows can be obtained.

First, the wireless LAN access point uniformly allocates the common communication-speed upper limit (a shaping upper limit) to each of the plurality of belonging mobile units or of the plurality of communicating mobile units. By doing so, equitable communication can be provided to each of the plurality of belonging mobile units or of the plurality of communicating mobile units.

Second, when the number of the belonging mobile units is less than the preset first threshold, or when the number of the communicating mobile units is less than the preset second threshold, even without imposing limitation to set the common communication-speed upper limit, each of the mobile units is allowed to communicate at a satisfactory communication speed. Thus, the shaping operation to allocate the common communication-speed upper limit (the shaping upper limit) to each of the mobile units is not performed. Meanwhile, when the number of the belonging mobile units is equal to or more than the preset first threshold, and when the number of the communicating mobile units is equal to or more than the preset second threshold, in order that each of the mobile units can equitably communicate, the shaping operation to allocate the common communication-speed upper limit to each of the mobile units is performed. By doing so, the shaping operation need not be unnecessarily performed, and hence application of unnecessary load to the wireless LAN access point can be reduced.

Third, a determination as to whether the shaping operation to allocate the communication-speed upper limit to each of the mobile units needs to be performed can be automatically made, and the shaping operation can be automatically performed without manpower intervention. Thus, a burden on an administrator of the wireless LAN access point can be reduced, and hence practical use is facilitated.

