JP2004253849A - Wireless communication system and communication control method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless system in which a reduction in a communication speed is decreased even when the number of terminal stations existing in a coverage area of a wireless base station is increased and to provide a communication control method therefor. <P>SOLUTION: A control apparatus 8 collates a preset traffic condition with traffic data of wireless base stations BS(#1, #2), transmits control information to set a beam pattern of beam variable antennas 1a, 1b provided in the wireless base stations BS(#1, #2) in accordance with the setting traffic condition to the wireless base stations BS(#1, #2), and controls the beam pattern of the beam variable antennas 1a, 1b to magnify or reduce the coverage area thereby decreasing the reduction in the communication speed even when the number of the terminal stations T is increased. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wireless communication system and a communication control method thereof.
[0002]
[Prior art]
FIG. 8 is a configuration diagram of a wireless communication system using a conventional wireless LAN system as an example.
[0003]
In FIG. 8, a conventional wireless communication system includes a wireless base station BSa connected to a higher-level network (LAN, backbone line, etc.) and a terminal station Ta (# 1 to # 1) performing data communication between the wireless base station BSa and the wireless base station BSa. #N), the wireless base station BSa transmits and receives a packet signal to and from the terminal station Ta by wireless communication via the antenna 2a.
[0004]
FIG. 9 is a block diagram showing a functional configuration of the above-described radio base station BSa. In FIG. 9, a radio base station BSa performs a bridge function for connecting to a higher-level network such as a LAN or a backbone line.
[0005]
The radio base station BSa modulates and demodulates a radio signal modulated at a predetermined frequency and a modulation rate with the terminal station Ta via the antenna 2a by the RF processing unit 3a, and converts it into a transmission / reception baseband signal. The antenna 2a usually uses a dipole-type omnidirectional antenna or a parabolic-type directional antenna, and the radio base station BSa communicates with the terminal station Ta within the coverage area of the antenna 2a. Perform communication.
[0006]
The communication control unit 4a monitors signals from the RF processing unit 3a and the MAC processing unit 5a, and sets a modulation speed at which a predetermined wireless communication quality is obtained in the RF processing unit 3a. Further, the base station sets the transmission speed of the baseband signal corresponding to the modulation speed in the MAC processing unit 5a, and transmits and receives packet signals to and from a higher-level network via the network interface 7a.
[0007]
The transmission rate at which packet signals are transmitted and received between the radio base station BSa and the terminal station Ta is a modulation rate determined by the radio communication quality, but as the number of terminal stations Ta increases (however, the maximum number of terminal stations Ta is The same frequency is shared and transmitted and received by a plurality of terminal stations Ta, so that the communication allocation time for each terminal station Ta decreases, and the throughput (effective transmission speed) decreases.
[0008]
In order to prevent a decrease in the throughput per terminal station Ta per station, it is conceivable to limit the number of terminal stations Ta accommodated per radio base station BSa, but the coverage area of the antenna 2a of the radio base station BSa can be changed. Since the number of terminal stations Ta in the coverage area cannot be reduced, the throughput (effective transmission rate) cannot be improved.
[0009]
For example, in a wireless communication system having wireless base stations in which an unspecified number of terminal stations called hot spots come and go, and the number of terminal stations increases and decreases, the coverage area cannot be reduced to reduce the number of terminal stations accommodated. However, the radio base station has to communicate with the increased number of terminal stations even if the transmission speed is reduced.
[0010]
As a method of preventing a decrease in transmission speed due to such an increase in the number of terminal stations, there is a method of increasing the number of communication channels by using a frequency band different from the frequency band in use. However, this method requires radio transceivers (circuits and antennas) corresponding to a plurality of frequency bands on the terminal station side, so that the terminal station side is complicated and expensive (for example, Non-Patent Document 1). reference.).
[0011]
In addition, since the frequency band to be added is limited, operating the wireless communication system by increasing the frequency band is not sufficient as a measure against a decrease in transmission speed.
[0012]
Furthermore, since the radio base station has a communication system in which the antenna coverage area is fixed, it is difficult to improve the communication speed by limiting the number of terminal stations that can be accommodated.
[0013]
In addition, there is a proposal for rotating an antenna to move a cover area and responding to a change in a terminal station (mobile phone) within the cover area (for example, see Patent Document 1).
[0014]
However, this method is merely a measure to follow the change in the number of mobile phones by simply rotating the antenna and changing the coverage area, and is a method of controlling traffic between adjacent base stations or terminal stations. It is not intended to cope with density fluctuations between base stations by expanding or reducing the coverage area.
[0015]
[Patent Document 1] Japanese Patent Application Laid-Open No. H11-225105 (4 pages, FIG. 4)
[0016]
[Non-Patent Document 1] Nikkei Communication July 15, 2002, p77-p79
[0017]
[Problems to be solved by the invention]
In this conventional wireless communication system, the antenna has a fixed beam pattern, and the wireless communication coverage area cannot be changed.
[0018]
In addition, a common frequency band is allocated and used between the wireless base station and a plurality of terminal stations, and when the number of terminal stations increases within the coverage area of the wireless base station, the wireless base station and the plurality of terminal stations are used. Since there is an upper limit on the transmission speed that can be transmitted to and from a station, in a system where the transmission speed is distributed (shared) by a plurality of terminal stations, a situation occurs in which the transmission speed per terminal station is insufficient. There was a problem.
[0019]
The present invention solves this problem. In order to limit the number of terminal stations existing in the antenna coverage area of the radio base station, the antenna coverage area is enlarged or reduced according to the traffic volume of the radio base station. It is an object of the present invention to provide a wireless communication system capable of adaptively changing a coverage area and reducing a decrease in communication speed even when the number of terminal stations increases as a whole system, and a communication control method thereof.
[0020]
[Means for Solving the Problems]
In order to achieve the above object, a wireless communication system according to the present invention includes a plurality of wireless base stations that wirelessly communicate with a plurality of terminal stations, and a wireless communication between the plurality of wireless base stations and the terminal stations. In a wireless communication system comprising a control device for monitoring and controlling, each of the wireless base stations, the number of the terminal stations communicating with the own station, the effective transmission rate between the own station and the terminal station, And a variable beam antenna capable of changing a beam pattern of an antenna with respect to the terminal station, wherein the control device is configured to control the traffic data transmitted from the plurality of radio base stations. And a predetermined traffic condition, and when the difference between the two is large, the beam pattern of the beam variable antenna of the radio base station having smaller traffic data is changed. Large, and characterized by comprising a beam control means for outputting a control signal so as to reduce the beam pattern of the beam variable antenna of the radio base station having a larger traffic data.
[0021]
In addition, the control method for a wireless communication system according to the present invention includes a plurality of wireless base stations that perform wireless communication with a plurality of terminal stations and include a beam variable antenna capable of changing an antenna beam pattern with respect to the terminal stations. And a control device for monitoring and controlling the wireless communication between the plurality of wireless base stations and the terminal station, wherein each of the wireless base stations includes The number of the terminal stations to communicate, and calculates the traffic data from the effective transmission rate between itself and the terminal station, the control device, the traffic data transmitted from the plurality of wireless base stations, Check the traffic conditions set in advance, if the difference between the two is large, expand the beam pattern of the beam variable antenna of the radio base station of the smaller traffic data, Communication control method for a wireless communication system, characterized in that said towards La Fick data is large reduces the beam pattern of the beam variable antenna of the radio base station.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0023]
FIG. 1 is a block diagram showing a configuration of a wireless communication system in which the present invention is applied to a wireless LAN system. The wireless base station BS (# 1, # 2) and the wireless base station BS (# 1, # 2) ), A control device 8 for controlling the radio base stations BS (# 1, # 2), a radio base station BS (# 1, # 2), and a LAN (local area) to which the control device 8 is connected. Network) 9, an upper network BN of the LAN 9, and a number of terminal stations T (# 1 to # 11) installed in the cover area C of the beam variable antennas 1a and 1b.
[0024]
The variable beam antennas 1a and 1b of the radio base stations BS (# 1 and # 2) are variably controlled in the range of the cover area C according to the beam control signal from the control device 8. For example, the variable beam antenna 1a is changed to cover areas C (#a) and C (#b). The beam variable antenna 1b is changed to cover areas C (#c) and C (#d). The coverage areas C (#a) and C (#c) have the same coverage area (width or diameter of the same extent), and the radio base stations BS (# 1) and (# 2) This is a cover area when the traffic volume is the same.
[0025]
These cover areas C (#a to #d) are information when the radio base station BS (# 1, # 2) detects the number of accommodation stations of the terminal station T covered by the beam variable antennas 1a, 1b, and the like. The data is transmitted to the control device 8 via the LAN 9 as traffic data.
[0026]
The control device 8 sets the coverage area of the beam variable antennas 1a and 1b based on the received traffic data. Then, the setting information is adjusted as a result of being sent back to the radio base stations BS (# 1, # 2) as a beam control signal to control the beam variable antennas 1a, 1b.
[0027]
In this communication system, between the terminal stations T arranged in the communication range of the beam variable antenna 1a or 1b (for example, the terminal stations 1 (# 1) and (# 4), or the terminal stations T (# 6) and (# 11 In the communication of)), the radio base station BS (# 1) or (# 2) relays the message signal.
[0028]
Further, between a terminal station T (for example, (# 1)) arranged in the communication range of the beam variable antenna 1a and a terminal station T (for example, (# 6)) arranged in the communication range of the beam variable antenna 1b. , The radio base stations BS (# 1) and (# 2) relay message signals.
[0029]
Further, communication between the terminal station T (for example, (# 1)) arranged in the communication range of the beam variable antenna 1a and a device (not shown) connected to the upper network BN is performed by the radio base station BS (# 1). ) Relays the message signal. Similarly, the communication between the terminal station T (for example, (# 6)) arranged in the communication range of the beam variable antenna 1b and the device connected to the upper network BN is performed by the radio base station BS (# 2). Relay.
[0030]
Then, the radio base stations BS (# 1 and # 2) respectively transmit information communicating with any of the terminal stations T (# 1 to # 11) and information on the transmission speed (modulation speed) of the radio communication. It is transmitted to the control device 8 as traffic data.
[0031]
FIG. 2 is a block diagram showing a functional configuration of the radio base stations BS (# 1, # 2), and FIG. 3 is a block diagram showing a functional configuration of the control device 8.
[0032]
Hereinafter, the configurations and operations of the radio base stations BS (# 1, # 2) and the control device 8 will be described with reference to FIGS.
[0033]
The wireless base station BS in FIG. 2 includes a variable beam antenna 1, an antenna beam control circuit 2, an RF processing unit 3, a communication control unit 4, a MAC processing unit 5, a communication management table 6, and a network interface 7.
[0034]
In FIG. 2, a radio packet signal transmitted and received by the radio base station BS to and from the terminal station T as a bridge device with the LAN 9 is input / output as a baseband signal via the network interface 7. Further, in the MAC processing unit 5, data relating to MAC control for transmitting the wireless packet signal is set, and the baseband signal is modulated and demodulated to a predetermined frequency and modulation speed by the RF processing unit 3, and the beam variable antenna 1 Sent from
[0035]
The wireless packet signal received by the variable beam antenna 1 is demodulated into a baseband signal by the RF processing unit 3, and data related to MAC control is read. Then, the communication control unit 4 sets data relating to MAC control in the baseband signal via the MAC processing unit 5 according to the read contents, and transmits the data to the network interface 7. When transmitting to the terminal station T, the power is transmitted to the RF processing unit 3 again.
[0036]
In the variable beam antennas 1a and 1b, the radiation beam pattern of the radio wave is controlled by the antenna beam control circuit 2, and the coverage area is enlarged or reduced. As the beam variable antenna 1, a phased array antenna, a patch antenna, a parabolic antenna whose mechanical structure changes, or the like is used.
[0037]
The antenna beam control circuit 2 operates according to a beam control signal transmitted from the control device 8 connected to the LAN 9, and the beam control signal is set based on the traffic amount between the radio base station BS and the terminal station T. .
[0038]
In the wireless LAN communication, the identification information of each terminal station T is set by the MAC address, and the MAC processing unit 5 of the wireless base station BS extracts the MAC address of the terminal station T from the received signal demodulated by the RF processing unit 3. You.
[0039]
The communication control unit 4 monitors the operation of the MAC processing unit 5, stores the MAC address of the communicating terminal station T in the communication management table 6, and stores the MAC address of the communicating terminal station T via the network interface 7. The address is transmitted as traffic data to the control device 8 connected to the LAN.
[0040]
In addition, the communication control unit 4 stores the set conditions extracted by the MAC processing unit 5 from the beam control signal from the control device 8 received via the network interface 7 in the communication management table 6, and controls the antenna beam control. Send to circuit 2.
[0041]
The setting condition of the beam control signal from the control device 8 is to control the beam width according to the traffic amount. The traffic amount is determined by the fact that the number of the terminal stations T accommodated by the radio base station BS is a predetermined value. By controlling the beam radiation patterns of the beam variable antennas 1a and 1b so as not to exceed the number, the cover area is enlarged or reduced.
[0042]
3, the control device 8 connected to the LAN 9 includes a network interface 78, a MAC processing unit 58, a communication control unit 48, and a communication management table 68.
[0043]
The control device 8 receives the traffic data transmitted from each wireless base station BS via the network interface 78. Then, the communication control unit 48 receives the traffic data (MAC address) extracted by the MAC processing unit 58 and stores it in the communication management table 68. Then, the number of terminal stations T communicating with each wireless base station BS is totaled.
[0044]
The communication management table 68 stores the number of terminal stations T accommodated for each radio base station BS and the transmission speed (modulation speed) between the radio base station BS and the terminal station T in a table. The controller 8 monitors the traffic data of the adjacent radio base stations BS while referring to the communication management table 68, and spreads the beam pattern between these radio base stations BS so that the traffic amount is averaged. Is controlled so that the number of terminal stations T accommodated is equal to or close to the same number.
[0045]
FIG. 4 is a conceptual diagram showing a configuration example of an antenna cover area according to the present invention. When the radio base stations BS (# 10) and (# 11) are installed adjacent to each other, the coverage area C (#x, #y, #z) of the radio base station BS (# 10) and the radio base station The cover diameter of the coverage area C (#k, #m, #n) of the BS (# 11) changes according to the traffic volume, and the traffic volume of each of the radio base stations BS (# 10) and (# 11) decreases. It shows that they are controlled to be the same.
[0046]
FIG. 5 shows the traffic amount for each coverage area C (#x, #y, #z, #k, #m, #n) of the radio base stations BS (# 10) and (# 11) corresponding to FIG. FIG. 3 is a diagram represented by a terminal station T accommodated. For example, the terminal stations T accommodated in the cover area C (#x) are three stations # 7, # 8, and # 9, and the corresponding terminal stations T accommodated in the cover area C (#k). Have the same number as the three stations # 10, # 11, and # 12. Similarly, in the cover areas C (#y) and (#m), and (#z) and (#n), the number of terminal stations T accommodated may be the same in three stations. It is shown.
[0047]
FIG. 6 shows that, in the communication system of FIG. 1, the control device 8 controls the respective coverage areas C (#a, #b) and (#c, #c, It is the figure which made the table the state of the traffic amount at the time of changing #d).
[0048]
FIG. 7 shows a beam variable antenna according to the number of terminal stations T accommodated by each of the radio base stations BS (# 1 and # 2) and the traffic amount based on the effective transmission speed with the terminal stations T. 9 is a flowchart illustrating an operation procedure for changing a cover area C by adjusting one beam.
[0049]
Hereinafter, an operation of adjusting the beam of the beam variable antenna 1 to change the cover area C will be described with reference to FIGS. 1, 6, and 7.
[0050]
In FIG. 1, the operation of complementing the coverage area between the radio base stations BS (# 1) and (# 2) is as follows. First, the radio base stations BS (# 1) and (# 2) A signal for requesting a reception response is transmitted to # 1 to # 11). Then, the number of terminal stations T that have responded is counted, and it is checked how many terminal stations T exist in the cover area C in which the own beam variable antennas 1a and 1b transmit and receive.
[0051]
That is, the radio base station BS (# 1) transmits a polling signal from the beam variable antenna 1a to each terminal station T (# 1 to # 4) for the cover area C (#a) set by default. When a response signal is transmitted from the terminal station T (# 1 to # 4) to this request, the MAC processing unit 5 of the radio base station BS (# 1) transmits the response signal from the terminal station T (# 1 to # 4). The MAC address included in the response signal is extracted (step s1 in FIG. 7).
[0052]
Next, the communication control unit 4 of the radio base station BS (# 1) stores the extracted MAC addresses of the terminal stations T (# 1 to # 4) in the communication management table 6, and also stores the extracted MAC addresses of the terminal stations T (# 1 to # 4). The number of # 4) is counted (step s2 in FIG. 7).
[0053]
Further, the MAC processing unit 5 monitors the baseband signal demodulated by the RF processing unit 3 while reading the MAC address, and checks the radio base station BS (# 1) and the terminal stations T (# 1 to # 4). Read the transmission speed between. The transmission speed (48 Mbps in this case) obtained here is recorded in the communication management table 6 as a part of the traffic data.
[0054]
Next, the communication control unit 4 reads the MAC address and the transmission speed of the terminal station T (# 1 to # 4) from the communication management table 6, and controls the traffic data through the MAC processing unit 5, the network interface 7, and the LAN 9 as traffic data. Transmit to the device 8.
[0055]
Similarly, the radio base station BS (# 2) also sends a polling signal from the beam variable antenna 1b to each terminal station T (# 5 to # 11) for the cover area C (#c) set by default. Send. Then, the MAC address and the transmission speed (also 48 Mbps) of the terminal station T (# 5 to # 11) obtained from the response signal are stored in the communication management table 6 of the radio base station BS (# 2), and The number of terminal stations T is totaled and transmitted to the control device 8 as traffic data together with the transmission speed.
[0056]
In the control device 8, when receiving traffic data from each of the radio base stations BS (# 1, # 2) via the network interface 78, the MAC processing unit 58 extracts the traffic data and receives the traffic data. Reference numeral 48 stores the MAC address data of the terminal station T accommodated for each radio base station BS (# 1, # 2) in the communication management table 68.
[0057]
Cover areas (#a) and (#c) in FIG. 6 are diagrams showing the contents of the communication management table 68 at this time. The transmission speed between the radio base station BS (# 1, # 2) and the terminal station T included in the traffic data is not shown in this figure, but is similarly stored in the communication management table 68. I have.
[0058]
Therefore, the communication control unit 48 of the control device 8 determines from the communication management table 68 the number of terminal stations T accommodated by each radio base station BS (# 1, # 2) and the transmission speed between the terminal stations T. And calculates the effective transmission speed with the terminal station T (step s3 in FIG. 7).
[0059]
In the radio base station BS (# 1), the transmission rate between the terminal stations T (# 1 to # 4) is 48 Mbps, and the number of terminal stations T accommodated is 4, so the effective transmission rate is: 48 ÷ 4 = 12 (Mbps). On the other hand, the effective transmission rate of the wireless base station BS (# 2) is 48 ÷ 7 = 6.8 (Mbps).
[0060]
The communication control unit 48 stores the obtained effective transmission speed in the communication management table 68 (step s4 in FIG. 7).
[0061]
Subsequently, the communication control unit 48 reads the number of the terminal stations T of the radio base station BS (# 1) from the communication management table 68 and checks whether the number is equal to or less than the reference value “7”. Then, since the number of terminal stations in the coverage area C (#a) of the beam variable antenna 1a is "4" (default value) and is equal to or less than the reference value "7", it is not necessary to change the coverage area C (#a). It is determined that there is not, and then the same determination is made for the wireless base station BS (# 2) (NO in step s5 in FIG. 7).
[0062]
Next, since the number of terminal stations T of the radio base station BS (# 2) is "7" (step s5 in FIG. 7 is YES), the communication control unit 48 further checks the effective transmission rate.
[0063]
The communication control unit 48 reads the effective transmission speed “6.8 Mbps” of the wireless base station BS (# 2) from the communication management table 68, and is equal to or less than the reference value “7 Mbps” of the effective transmission speed (YES in step s6 in FIG. 7). Judge. Therefore, the communication control unit 48 determines whether the beam pattern of the beam variable antenna 1a of the radio base station BS (# 1) can be expanded and the number of terminal stations T can be increased.
[0064]
The communication control unit 48 reads the effective transmission speed “12 Mbps” of the wireless base station BS (# 1) from the communication management table 68 and determines that the effective transmission speed is equal to or higher than the reference value “7 Mbps” (YES in step s8 in FIG. 8). As a result, it is determined that the number of terminal stations T of the radio base station BS (# 1) can be increased. Then, it is found that the radio base station BS (# 1) can accommodate at least one of the terminal stations T of the radio base station BS (# 2), and the beam variable between the radio base stations BS (# 1) and (# 2) is changed. The beam pattern for enlarging or reducing the coverage area of the antennas 1a and 1b is changed (Step 9 in FIG. 7).
[0065]
The following is a detailed description of the beam pattern control in step 9.
[0066]
The communication control unit 48 of the control device 8 transmits a beam expansion control signal to the beam variable antenna 1a of the radio base station BS (# 1) via the network interface 78, and transmits a control signal of the radio base station BS (# 2). A beam reduction control signal is transmitted to the beam variable antenna 1b.
[0067]
When the radio base station BS (# 1) receives a beam control signal for enlarging the coverage area from the control device 8 via the network interface 7, the communication control unit 4, which has been monitoring the MAC processing unit 5, changes the communication management table. 6, a parameter for the coverage area C (#b) is set in the antenna beam control circuit 2, and the terminal transmits the polling signal again in the coverage area C (#b) in the same manner as the operation by the polling signal described above. Transmit to the stations T (# 1 to # 5).
[0068]
When receiving the response signal from the terminal station T (# 1 to # 5), the communication control unit 4 of the wireless base station 8 reads the MAC address of the terminal station T (# 1 to # 5) and accommodates it. It is detected that the number of the terminal stations T (# 1 to # 5) has become five. Then, the MAC address of the terminal station T (# 1 to # 5) is stored in the communication management table 6, and the effective transmission speed (48/5 = 9.6 Mbps) is similarly obtained. Is generated and transmitted to the control device 8.
[0069]
On the other hand, the radio base station BS (# 2) sets the traffic data when the radio base station BS (# 2) is set in the cover area C (#d) in the same procedure as the radio base station BS (# 1), that is, the accommodated terminal station. The MAC addresses of the six stations T (# 6 to # 11) and the effective transmission speed (48/6 = 8.0 Mbps) are stored in the communication management table 6, and the traffic data is transmitted to the control device 8.
[0070]
Then, the control device 8 repeats this procedure, and if a determination of No is obtained in any of the steps s5 to s8 in FIG. 7, at that time, the beam pattern setting for the radio base station BS is performed. Then, the state returns to the state of monitoring the traffic data from the wireless base station BS again, and thereafter, the wireless LAN communication of the packet signal carrying the message is constantly started with the terminal station T.
[0071]
The above beam pattern control sets a fine coverage area range by changing the spread of the beam little by little, but it is not possible to electronically control a continuous beam pattern like a phased array antenna, for example, In the case of a patch antenna or a variable beam antenna in which a beam pattern is set stepwise so as to switch a mechanical structure, the beam control procedure may be simplified.
[0072]
For example, in a beam variable antenna in which the antenna beam can be adjusted only in two stages, the terminal station T accommodated by the radio base station BS and the effective transmission speed are obtained as traffic data using the two beam patterns, and the distance between adjacent radio base stations BS is determined. It is sufficient to select and set the beam pattern of the set with the smaller difference in the number of terminal stations T accommodated in.
[0073]
Further, even with an antenna whose beam pattern can be continuously controlled, a method in which several beam patterns are set in advance and a beam pattern having a small difference in the number of accommodated terminal stations between the radio base stations BS may be selected from among them. . Then, the effective transmission rate may be used as a reference of the traffic amount when changing the area of the cover area.
[0074]
Further, in the above description, the detection of the number of terminal stations T performed by the radio base station BS is performed by the means for reading the MAC address. The detection may be performed based on the IP address associated with the terminal station T.
[0075]
In the above description, the control device 8 is independently installed in the wireless communication system. However, one of the wireless base stations BS (for example, # 1) may also serve as the control device 8. .
[0076]
As described above, the embodiments of the present invention have been described by taking a wireless base station of a wireless LAN system as an example, but the present invention may be applied to a wireless communication system such as a mobile phone base station or a mobile communication base station.
[0077]
【The invention's effect】
As described above, according to the present invention, the antenna coverage area is enlarged or reduced according to the traffic volume of the radio base station, the antenna coverage area is adaptively changed, and the communication speed is increased even when the number of terminal stations increases. Can be reduced.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a wireless communication system according to the present invention.
FIG. 2 is a block diagram showing components of a wireless base station according to the present invention.
FIG. 3 is a block diagram showing components of a control device of the present invention.
FIG. 4 is a conceptual diagram showing a configuration example of an antenna cover area according to the present invention.
FIG. 5 is a diagram of a communication management table in which a cover area in FIG. 4 is set.
FIG. 6 is a diagram of a communication management table referred to for controlling an antenna beam pattern.
FIG. 7 is a flowchart showing a procedure of an antenna beam control operation by the control device of the present invention.
FIG. 8 is a block diagram showing a configuration of a conventional wireless communication system.
FIG. 9 is a block diagram showing components of a conventional radio base station.
[Explanation of symbols]
1 beam variable antenna
2 Antenna beam control circuit
2a antenna
3, 3a RF processing circuit
4, 48, 4a Communication control unit
5, 58, 5a MAC processing unit
6,68 Communication management table
7, 78, 7a Network interface
8 Control device
9 LAN (Local Area Network)
BS radio base station
BN upper network
T, Ta terminal station
C Antenna cover area

Claims (5)

A plurality of wireless base stations for wireless communication with a plurality of terminal stations;
In a wireless communication system including a control device that monitors and controls wireless communication between the plurality of wireless base stations and the terminal station,
Each of the wireless base stations,
Calculating means for calculating traffic data from the number of the terminal stations communicating with the own station and an effective transmission rate between the own station and the terminal station;
A beam variable antenna capable of changing a beam pattern of an antenna for the terminal station,
The control device includes:
The traffic data transmitted from the plurality of radio base stations is compared with a preset traffic condition, and when the difference between the two is large, the beam pattern of the beam variable antenna of the radio base station having the smaller traffic data is used. And a beam control means for outputting a control signal to reduce a beam pattern of the beam variable antenna of the radio base station having larger traffic data. The beam control means of the control device,
The traffic data of the first radio base station and the traffic data of the second radio base station adjacent to the first radio base station are compared with each other, and the beam variable antenna of the beam variable antenna is reduced so that the difference in traffic volume between the first and second radio radio base stations is reduced. The wireless communication system according to claim 1, wherein a beam pattern is controlled to expand or reduce the coverage area of the first and second wireless base stations. The wireless communication system according to claim 1, wherein one of the wireless base stations also serves as the control device. A plurality of radio base stations, comprising: a plurality of radio base stations comprising a beam variable antenna capable of performing radio communication with a plurality of terminal stations and changing an antenna beam pattern with respect to the terminal stations; and the plurality of radio base stations and the terminal stations. And a control device for monitoring and controlling the wireless communication between the communication control method of the wireless communication system comprising:
Each of the wireless base stations,
The traffic data is calculated from the number of the terminal stations communicating with the own station and the effective transmission speed between the own station and the terminal station,
The control device includes:
The traffic data transmitted from the plurality of radio base stations is compared with a preset traffic condition, and when the difference between the two is large, the beam pattern of the beam variable antenna of the radio base station having the smaller traffic data is used. And controlling the beam pattern of the beam variable antenna of the wireless base station having the larger traffic data. The control device includes:
The traffic data of the first radio base station and the traffic data of the second radio base station adjacent to the first radio base station are compared with each other, and the beam variable antenna of the beam variable antenna is reduced so that the difference in traffic volume between the first and second radio radio base stations is reduced. The communication control method for a wireless communication system according to claim 4, wherein the beam pattern is controlled to increase or decrease the coverage area of the first and second wireless base stations.

Images