JP2005333510A - Controller and control method for radio communication - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication controller capable of eliminating radio wave interference to provide satisfactory throughput by performing channel change in accordance with a substantial traffic amount without affecting normal communication by a radio LAN. <P>SOLUTION: When radio communication connection to an electronic device terminal is made by selectively setting a plurality of frequency channels in a radio network system, the radio wave level for each of the plurality of frequency channels is measured on the basis of a signal received by a radio antenna, the measured data is compared with a prescribed threshold to determine the use or nonuse for each frequency channel, and the determination result is stored as statistical data for each frequency channel. While radio communication is performed with the electronic device terminal, frequency channels are changed on the basis of the statistical data as needed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a radio communication technique, and more particularly to a radio communication control apparatus and a control method therefor provided in an access point (AP) or a station (terminal).

In recent years, a wireless LAN (Local Area Network) has been introduced in offices, homes, and the like in consideration of easiness of installation and economics of introduction costs. The wireless LAN can move each terminal forming the wireless LAN within a communicable range as compared to the wired LAN used before the introduction of the wireless LAN, that is, it has high mobility. The boundaries that indicate possible ranges are ambiguous. Since the boundary indicating the communicable range is ambiguous, when a plurality of wireless LANs exist adjacent to each other, the terminal exists in a range where the communicable ranges of the plurality of wireless LANs overlap. Sometimes. The terminal (hereinafter referred to as a terminal existing in the overlapping range) receives respective radio waves in the wireless LAN adjacent to each other, which may cause a radio wave interference problem and reduce throughput.

As a method for solving the above-described problem, there is a method in which transmission / reception of a wireless LAN is temporarily stopped and then scanning is performed to rearrange channels. (See Patent Document 1)
JP 2002-158667 A

  However, the conventional technique disclosed in Patent Document 1 is a channel that performs scanning after temporarily stopping transmission / reception of a wireless LAN in order to eliminate radio wave interference that occurs when the wireless communication device group performs wireless communication. Therefore, the transmission / reception by normal wireless communication is affected. In addition, since only the presence / absence of an access point is confirmed in this scan, it is impossible to grasp the channel (frequency) usage status by the network.

  Therefore, in the present invention, there is provided a wireless communication control apparatus that changes a channel according to a substantial traffic volume without affecting normal communication by a wireless LAN, and cancels radio wave interference to obtain a good throughput. The purpose is to provide.

  In order to achieve the above object, in the invention according to claim 1, wireless communication control for controlling wireless communication control by selectively setting a plurality of frequency channels in a wireless network system and establishing wireless communication connection with an electronic device terminal In the apparatus, a frequency control unit that extracts a signal of a predetermined frequency from a signal received from a radio antenna, a data processing unit that extracts desired data from a frame of the signal extracted from the frequency control unit, and a signal received by the radio antenna A radio wave level measuring unit that measures the radio wave level for each of a plurality of frequency channels in a predetermined cycle, and the data measured by the radio wave level measuring unit is compared with a predetermined threshold value or used for each frequency channel. The channel usage status determination unit that determines whether it is unused, and the determination result by this usage status determination unit for each frequency channel And statistical data storage unit that stores as statistical data, during the execution of the electronic equipment terminal and the wireless communication, to provide wireless communication control apparatus and a change processing unit for changing the frequency channel based on statistical data.

  In the invention according to claim 5, in the wireless communication control device that establishes wireless communication connection with the electronic device terminal by selectively setting a plurality of frequency channels in the wireless network system and receives wireless communication control, reception from the wireless antenna A frequency control unit that extracts a signal of a predetermined frequency from the acquired signal, a data processing unit that extracts desired data from the frame of the signal extracted from the frequency control unit, and a plurality of frequencies based on the signal received by the wireless antenna A radio wave level measurement unit that measures the radio wave level for each channel at a predetermined cycle, and a channel use that determines whether the frequency channel is used or not by comparing the data measured by the radio wave level measurement unit with a predetermined threshold Received from the electronic device terminal via the situation determination unit and the determination result by the usage status determination unit and the wireless antenna Based on data indicating the frequency of use for each frequency channel within the radio communication range of the slave device terminal, a statistical data storage unit for storing statistical data indicating the frequency of use for each frequency channel, and executing wireless communication with the electronic device terminal And a change processing unit that changes a frequency channel based on statistical data.

  According to the present invention, a radio communication control apparatus that changes a channel according to a substantial traffic amount without affecting normal communication by a wireless LAN, eliminates radio wave interference, and obtains good throughput. Can be provided.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing an embodiment of a wireless network system according to the present invention.
This system includes APs (access points) 1 to AP4 that serve as radio communication control stations that perform frequency channel control and the like, and terminals 1a, 2a, 3a, 4a, and 4b that are connected to these AP1 to AP4 by radio communication, respectively. It is configured.

AP1 is configured to be capable of wireless communication connection with terminal 1a, AP2 with terminal 2a, AP3 with terminal 3a, and AP4 with terminal 4a and terminal 4b.
A BSA (basic service area) 5 indicates a wireless communicable range centering on the AP 1. A terminal 1a capable of wireless communication with AP1 can perform wireless communication with AP1 within BSA5, and AP2 to AP4 each have a BSA (basic service area).

Here, each of the AP1 to AP4 can selectively set three frequency channels A to C and wirelessly communicate with each terminal. In the example of FIG. 1, AP1 communicates with the terminal 1a through the channel A. AP2 also communicates with terminal 2a via channel A, AP3 communicates with terminal 3a via channel C, and AP4 communicates with terminals 4a and 4b via channel A.

FIG. 2 is a block diagram showing a configuration of a wireless communication control apparatus according to an embodiment of the present invention.
The wireless communication control device 6 shown in FIG. 2 is provided in the APs 1 to 4 and the terminals 1a to 4a and 4b. In the present embodiment, a case where the wireless communication control device 6 is provided in the APs 1 to 4 will be described.
The radio communication control device 6 includes a radio antenna 7 that receives a signal communicated by radio, and a RF (Phase Locked Loop) circuit that extracts a signal of a predetermined frequency from the signal received by the radio antenna 7. (Radio frequency control) unit 8, baseband processing unit 9 for extracting desired data from the frame of the signal extracted by the RF unit, and data extracted by the baseband processing unit 9 are input and wireless communication control is performed. A CPU 10 for overall control of the device 6, a signal having a predetermined frequency from a signal received by the radio antenna 7, a power measuring unit 11 for measuring a radio wave level (power amount) in each frequency channel, and this power measurement The measurement channel is changed by the unit 11 and its timing is controlled, and the measurement result is input to each frequency channel. Performs use / unused determination Le, and a control arithmetic unit 12 for holding the measurement result as statistical data.

FIG. 3 is a diagram illustrating a measurement procedure for each frequency channel by the power measurement unit 11.
In each channel A to C, power is measured in a short time with a relatively short period (600 μs). When carrier sense is executed for each of the frequency channels A to C within the period while shifting the time, and the measured power in each frequency channel is greater than a preset threshold (−60 dB), the channel is being used or is small Is determined to be unused.

FIG. 4 shows an example of the statistical data table 13 of AP1 held in the control calculation unit 12.
The statistical data table 13 holds data on the number of detections for which the use of each of the selectable frequency channels A to C is detected and the usage rate indicating the ratio of the number of detections to the total number of measurements. In the example of FIG. 4, the number of detections of channel A is about 100,000 times (use rate 80%), channel B is 10,000 times (use rate 10%), and channel C is 30,000 times (use rate 40%). Therefore, in BSA1, the usage rate of channel A is high and the usage rate of channel B is low.

Next, the operation of the wireless communication control device in the first embodiment will be described with reference to FIG. Here, a description will be given from a state in which the terminal 1a executes a communication request to the AP1, the AP1 assigns the channel A to the request, and wireless communication has already been established between the terminal 1a and the AP1.

When wireless communication is established between AP1 and terminal 1a, when terminal 1a issues a streaming video data distribution request that requires a bandwidth of, for example, 20 Mbps to AP1, CPU 10 of AP1 performs QoS (Quality). of Service) It is determined that the request is large (step 1), and the statistical data table 13 of the control calculation unit 12 is referred to and the channel usage rates of the channels A to C are confirmed (step 2). As a result of confirmation in step 2, for example, if there is a channel having a lower usage rate than channel A, for example channel B (step 3), as shown in FIG. (Step 4). After changing to channel B in step 4, compare the throughput when communicating on channel A and the communication throughput on channel B after the change (step 5). Continue communication on channel B.

If it is determined in step 3 that the current channel A is optimal, the current channel A is not changed as it is. If the throughput in channel B after the change in step 5 is not improved as compared with the throughput in channel A, communication is performed after returning to channel A again (step 6).

  As described above, according to the first embodiment of the present invention, the power measurement unit 11 of the wireless communication control device 6 periodically checks the usage status of each frequency channel A to C, and the determination result is the statistical data table 13. If the QoS request from the terminal 1a is large, the channel can be switched to a less frequently used channel by referring to the statistical data table 13, so that the communication between the AP1 and the terminal 1a is continued as needed. Can be automatically changed to a less frequently used channel. Further, when the throughput after the channel change is not improved, the channel is returned to the channel before the change, so that the channel switching control reflecting the channel congestion state can be performed.

In this embodiment, the carrier sense cycle of each frequency channel A to C is 600 μs, but this corresponds to the minimum frame length of a signal to be wirelessly communicated, and the channel is used by setting this cycle. The situation can be executed accurately and without overloading the wireless communication control device. Especially, the cycle can be further shortened to obtain a more accurate usage status, or the cycle can be reversed. The calculation load may be reduced by increasing the length.

Further, although the wireless antenna 7 is configured to be shared for power measurement by the power measurement unit 11, another antenna may be prepared for the power measurement unit 11.
Further, in the present embodiment, the channel change process is executed when the QoS request from the terminal 1a is large, but the channel change process may be executed every predetermined time or every predetermined request.

FIG. 6 is a schematic configuration diagram showing a wireless network system for explaining a modification example in which the terminals 1a to 4a and 4b are also provided with the wireless communication control device 6 in the first embodiment of the present invention. .

In FIG. 6, two access points AP1 and AP2 and a terminal 1b and a terminal 2b connected to the wireless communication are shown for the sake of simplicity.
The terminal 1b is provided with a wireless communication control device 6 similar to AP1, and is configured to be able to perform wireless communication using any one of AP1 and frequency channels A to C.
The wireless communication range 14 indicates the wireless communication range of the terminal 1b.
The terminal 1b confirms the usage status of each of the frequency channels A to C in the same manner as AP1, holds a statistical data table as shown in FIG. 4, and transmits the data of the table to AP1. Since AP1 can obtain the statistical data from the terminal 1b, the AP1 uses the frequency channels A to C in the wireless communication range 14 of the terminal 1b in addition to the usage status of the frequency channels A to C in its own BSA5. It is possible to hold a statistical data table that also considers the usage status of C.

According to this configuration, when AP2 communicates with terminal 2b and channel A as shown in FIG. 6, since AP1 cannot detect the channel usage status between AP2 and terminal 2b, terminal 1b actually The problem that the terminal 1b continues the wireless communication between the AP1 and the channel A by determining that the usage frequency of the channel A is low in spite of the high frequency of using the channel A in the wireless communication range 14 is eliminated. Will be able to.

Therefore, by providing the wireless communication control device 6 also in the terminal 1b, it is possible to connect the wireless communication between the AP 1 and the terminal 1b with a stable frequency channel that is less frequently used.

1 is a schematic configuration diagram showing an embodiment of a wireless network system according to the present invention. It is a block diagram which shows the structure of the radio | wireless communication control apparatus which is one Embodiment of this invention. It is a figure which shows the measurement procedure according to each frequency channel by an electric power measurement part. 2 shows an example of a statistical data table held in a wireless communication control device. It is a flowchart figure explaining operation | movement of the radio | wireless communication control apparatus in 1st embodiment of this invention. It is a system schematic block diagram for demonstrating the modification at the time of providing a radio | wireless communication control apparatus in a terminal.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... AP (access point), 1a ... terminal, 5 ... BSA (basic service area), 6 ... Wireless communication control apparatus, 7 ... Wireless antenna, 8 ... RF part, DESCRIPTION OF SYMBOLS 9 ... Baseband process part, 10 ... CPU, 11 ... Electric power measurement part, 12 ... Control calculating part, 13 ... Statistical data table.

Claims (7)

In a wireless communication control device that selectively sets a plurality of frequency channels in a wireless network system to establish a wireless communication connection with an electronic device terminal and controls wireless communication,
A frequency control unit that extracts a signal of a predetermined frequency from the signal received from the wireless antenna;
A data processing unit for extracting desired data from the frame of the signal extracted from the frequency control unit;
A radio wave level measuring unit that measures a radio wave level for each of the plurality of frequency channels at a predetermined period based on a signal received by the radio antenna;
A channel usage status determining unit that determines whether each frequency channel is used or not by comparing the data measured by the radio wave level measuring unit with a predetermined threshold;
A statistical data storage unit for storing the determination result by the usage status determination unit as statistical data of the usage frequency for each frequency channel;
A change processing unit that changes the frequency channel based on the statistical data during wireless communication with the electronic device terminal;
A wireless communication control device comprising:   The radio communication control apparatus according to claim 1, wherein the predetermined period is a time shorter than the frame length.   The radio communication control apparatus according to claim 1, wherein the change processing unit executes the change process of the frequency channel based on the statistical data only when there is a predetermined request from the electronic device terminal. In a wireless communication control device that selectively sets a plurality of frequency channels in a wireless network system to establish a wireless communication connection with an electronic device terminal and controls wireless communication,
A frequency control unit for extracting a signal of a predetermined frequency from the signal received from the first wireless antenna;
A data processing unit for extracting desired data from the frame of the signal extracted from the frequency control unit;
A radio wave level measuring unit that measures a radio wave level for each of the plurality of frequency channels at a predetermined period based on a signal received by a second radio antenna;
A channel usage status determining unit that determines whether each frequency channel is used or not by comparing the data measured by the radio wave level measuring unit with a predetermined threshold;
A statistical data storage unit for storing the determination result by the usage status determination unit as statistical data of the usage frequency for each frequency channel;
A change processing unit that changes the frequency channel based on the statistical data during wireless communication with the electronic device terminal;
A wireless communication control device comprising: In a wireless communication control device that selectively sets a plurality of frequency channels in a wireless network system to establish a wireless communication connection with an electronic device terminal and controls wireless communication,
A frequency control unit that extracts a signal of a predetermined frequency from the signal received from the wireless antenna;
A data processing unit for extracting desired data from the frame of the signal extracted from the frequency control unit;
A radio wave level measuring unit that measures a radio wave level for each of the plurality of frequency channels at a predetermined period based on a signal received by the radio antenna;
A channel usage status determining unit that determines whether each frequency channel is used or not by comparing the data measured by the radio wave level measuring unit with a predetermined threshold;
Based on the determination result by the use state determination unit and data indicating the frequency of use for each frequency channel within the wireless communication range of the electronic device terminal received from the electronic device terminal via the wireless antenna, for each frequency channel A statistical data storage unit for storing statistical data indicating the usage frequency of
A change processing unit that changes the frequency channel based on the statistical data during wireless communication with the electronic device terminal;
A wireless communication control device comprising: In a wireless communication control method for selectively setting a plurality of frequency channels in a wireless network system and establishing a wireless communication connection with an electronic device terminal to control wireless communication,
Extract a signal of a predetermined frequency from the signal received from the wireless antenna,
Extract the desired data from the frame of the signal extracted by this frequency control unit,
Based on the signal received by the wireless antenna, the radio wave level for each of the plurality of frequency channels is measured at a predetermined period,
The measured data is compared with a predetermined threshold value to determine whether each frequency channel is used or not used.
This determination result is stored as statistical data of the frequency of use for each frequency channel,
A wireless communication control method, wherein the frequency channel is changed based on the statistical data as necessary during wireless communication with the electronic device terminal. In a wireless communication control method for selectively setting a plurality of frequency channels in a wireless network system and establishing a wireless communication connection with an electronic device terminal to control wireless communication,
Extract a signal of a predetermined frequency from the signal received from the wireless antenna,
Extract the desired data from the frame of the signal extracted by this frequency control unit,
Based on the signal received by the wireless antenna, the radio wave level for each of the plurality of frequency channels is measured at a predetermined period,
The measured data is compared with a predetermined threshold value to determine whether each frequency channel is used or not used.
Based on the determination result and the data indicating the usage frequency for each frequency channel within the wireless communication range of the electronic device terminal received from the electronic device terminal via the wireless antenna, the usage frequency for each frequency channel is indicated. Remember statistical data,
A wireless communication control method, wherein the frequency channel is changed based on the statistical data as necessary during wireless communication with the electronic device terminal.

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