JP4759608B2 - Wireless LAN system - Google Patents

Description

  The present invention relates to a wireless LAN system in which a base station and a wireless communication terminal perform wireless communication via a leaky transmission line within a narrow communication area.

Conventionally, in a wireless LAN system using a leaky transmission path, a communication area called a service area or a cell is formed along the leaky transmission path, and a wireless communication terminal performs data communication with a base station via the leaky transmission path. For example, a system is known, and for example, each of a plurality of base stations is provided with an aerial line by a leaky coaxial line, and each base station is arranged along a moving path of the mobile station, and within a predetermined electric field strength range from the aerial line. A mobile station in a communication area includes a mobile station that performs wireless communication with a base station via a leaky coaxial line in the same communication area (see, for example, Patent Document 1).
JP-A-11-75250

  Although the thing of patent document 1 can comprise a communication area along a leaky transmission path because the electric field strength radiated | emitted from a leaky coaxial line is small, the electric field strength radiated | emitted from a mobile station is the leaky coaxial line. The problem is that the electric field from the mobile station in the adjacent communication area becomes an interference wave and the own radio wave also becomes an interference wave to the mobile station in the adjacent communication area. was there.

  Therefore, the present invention provides a wireless LAN system capable of preventing radio wave interference with wireless communication terminals in different communication areas as much as possible.

The present invention relates to a wireless LAN system in which a plurality of communication areas formed by connecting leaky transmission lines to a base station are arranged, and a wireless communication terminal performs wireless communication with the base station via the leaky transmission lines in each communication area. When a radio communication terminal receives a transmission radio wave from a radio communication terminal in another communication area that performs radio communication using the same channel, the channel for radio communication is assigned to each base station in each communication area . While requesting the wireless communication terminal in the communication area to reduce the transmission power, the wireless communication terminal reduces the transmission power to the minimum necessary when performing wireless communication with the base station in the communication area in which it exists.

  According to the present invention, it is possible to provide a wireless LAN system capable of preventing radio wave interference with wireless communication terminals in different communication areas as much as possible.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
This embodiment is an example based on another viewpoint, and describes a wireless communication system in which a wireless communication terminal wirelessly communicates with a base station according to a preset transmission power.

  As shown in FIG. 1, one end of each of the leaky transmission paths 12, 22, 32, 42, 52, 62 is connected to a plurality of base stations 11, 21, 31, 41, 51, 61, and The other ends are connected to terminators 13, 23, 33, 43, 53, 63, respectively, and communication areas 1, 2, called service areas along the respective leaky transmission paths 12, 22, 32, 42, 52, 62 are provided. 3, 4, 5 and 6 are formed.

  The communication areas 1, 2, 3, 4, 5, 6 are arranged in a line at a predetermined interval so as not to overlap each other, and the communication areas 4, 5, 6 communicate with each other. They are arranged in a row so as to be parallel to the areas 1, 2, and 3. Channels Ch1, Ch3, Ch1, Ch2, Ch4, and Ch2 for wireless communication are assigned to the base stations 11, 21, 31, 41, 51, and 61, respectively.

  Accordingly, each channel is a channel assigned to each communication area 1, 2, 3, 4, 5, 6, and the same channel Ch1 is assigned to the communication area 1 and the communication area 3 with the communication area 2 in between. The same channel Ch2 is allocated to the communication area 4 and the communication area 6 with the communication area 5 interposed therebetween.

  In each of the communication areas 1, 2, 3, 4, 5, and 6, the base stations 11, 21, 31, 41, 51, and 61 are respectively connected via leaky transmission lines 12, 22, 32, 42, 52, and 62. There are wireless communication terminals 14, 24, 34, 44, 54, and 64 that perform wireless communication.

  Each of the wireless communication terminals 14, 24, 34, 44, 54, 64 is connected to a circulator 72 by a transmitting / receiving antenna 71 that transmits and receives wireless signals, as shown in FIG. The circulator 72 supplies the reception signal received by the transmission / reception antenna 71 to the reception amplifier 73. The amplifier 73 amplifies the received signal and supplies it to the receiver 74. The receiver 74 demodulates the received signal and supplies it to the controller 75.

  The controller 75 controls the transmitter 76 together with the receiver 74. The transmitter 76 modulates the transmission signal and supplies it to the transmission amplifier 77. The amplifier 77 amplifies the transmission signal and supplies it to the circulator 72. The circulator 72 outputs a transmission signal to the transmission / reception antenna 71.

  The wireless communication terminals 14, 24, 34, 44, 54, 64 communicate with the control unit 75 the channel arrangement status and communication of the base stations 11, 21, 31, 41, 51, 61 as shown in FIG. A storage unit 78 that stores whether the transmission power in the area is “strong” or “weak” is provided. That is, in the storage unit 78, channels Ch1, Ch3, Ch1, Ch2, Ch4, and Ch2 are assigned to the base stations 11, 21, 31, 41, 51, and 61, respectively, and the communication areas 1, 2, 3, and 3 are assigned. In 4, 5, and 6, it is stored that the transmission power is “weak”, “strong”, “weak”, “weak”, “strong”, “weak”.

  With this configuration, the wireless communication terminal 14 in the communication area 1 performs communication with the transmission power set to “weak” when communicating with the base station 11. The wireless communication terminal 24 in the communication area 2 communicates with the transmission power set to “strong” when communicating with the base station 21. When communicating with the base station 31, the wireless communication terminal 34 in the communication area 3 performs communication with the transmission power set to “weak”.

  The wireless communication terminal 44 in the communication area 4 performs communication with the transmission power set to “weak” when communicating with the base station 41. When communicating with the base station 51, the wireless communication terminal 54 in the communication area 5 performs communication with the transmission power set to “strong”. When communicating with the base station 61, the wireless communication terminal 64 in the communication area 6 performs communication with the transmission power set to “weak”.

  As described above, the wireless communication terminal 14 in the communication area 1 and the wireless communication terminal 34 in the communication area 3 wirelessly communicate with the base stations 11 and 31 using the same wireless channel CH1, respectively, but their transmission powers are “weak”. Therefore, they do not receive unwanted radio waves. In addition, the wireless communication terminal 44 in the communication area 4 and the wireless communication terminal 64 in the communication area 6 perform wireless communication with the base stations 41 and 61 using the same wireless channel CH2, respectively, but the transmission power of each other becomes “weak”. Therefore, they do not receive unnecessary radio waves.

  In addition, since the wireless channels are CH3 and CH4 in the communication area 2 and the communication area 5, the communication on the same channel is not performed in the vicinity, so the wireless communication terminals 24 and 54 have the transmission power “strong” and the base station Even if it communicates with 21 and 51 by radio | wireless, it does not give an electric field interference with respect to the periphery. Thus, mutual radio wave interference in each of the communication areas 1 to 6 can be prevented as much as possible.

  Each wireless communication terminal 14, 24, 34, 44, 54, 64 has a storage unit 78 that stores the channel arrangement status of each base station and whether the transmission power in the communication area is “strong” or “weak”. For example, when the wireless communication terminal 14 in the communication area 1 moves to the communication area 2, the wireless communication area 14 is connected to the base station 21 and the transmission power “strong” according to the setting information in the storage unit 78. Wireless communication begins. Conversely, when the wireless communication terminal 24 in the communication area 2 moves to the communication area 1, the wireless communication area 24 communicates with the base station 11 with the transmission power “weak” according to the setting information in the storage unit 78. To do. Thus, mutual radio wave interference can be prevented as much as possible even when the wireless communication terminals move to different communication areas.

  In this way, when a wireless communication terminal communicates with a base station that may cause radio wave interference by storing the channel arrangement status of the base station and the presence / absence of radio wave interference from the arrangement status in advance. Communication is performed with the transmission output lowered. Thereby, it is possible to always communicate with the base station without receiving unnecessary radio waves.

(Second Embodiment)
In this embodiment, when a radio communication terminal receives a transmission radio wave from a radio communication terminal in another communication area in which radio communication is performed using the same channel or an adjacent channel, the self-existence directly exists to the radio communication terminal. A wireless communication system that wirelessly transmits a signal requesting a decrease in notification transmission power and that reduces its own transmission power will be described.

As shown in FIG. 4, the wireless communication terminal 15 exists in the communication area 1, the wireless communication terminal 35 exists in the communication area 3, and the wireless communication terminal 45 exists in the communication area 4.
As shown in FIG. 5, the wireless communication terminals 15, 35, and 45 communicate wirelessly with the base stations 11, 31, and 41 through leaky transmission paths 12, 32, and 42 in the communication areas 1, 3, and 4. The first wireless communication unit 80, a second wireless communication unit 90 for performing wireless communication with wireless communication terminals in other communication areas, and a control unit 100 that controls these communication units.

  The first wireless communication unit 80 connects a transmission / reception antenna 81 for transmitting / receiving a wireless signal to a circulator 82. The circulator 82 supplies the reception signal received by the transmission / reception antenna 81 to the reception amplifier 83. The amplifier 83 amplifies the received signal and supplies it to the receiver 84. The receiver 84 demodulates the received signal and supplies it to the control unit 100.

  The controller 100 controls the transmitter 85 together with the receiver 84. The transmitter 85 modulates the transmission signal and supplies it to the transmission amplifier 86. The amplifier 86 amplifies the transmission signal and supplies it to the circulator 82. The circulator 82 outputs a transmission signal to the transmission / reception antenna 81.

  The second wireless communication unit 90 is connected to a circulator 92 by a transmission / reception antenna 91 that transmits and receives wireless signals. The circulator 92 supplies the reception signal received by the transmission / reception antenna 91 to the reception amplifier 93. The amplifier 93 amplifies the received signal and supplies it to the receiver 94. The receiver 94 demodulates the received signal and supplies it to the control unit 100.

  The controller 100 controls the transmitter 95 together with the receiver 94. The transmitter 95 modulates the transmission signal and supplies it to the transmission amplifier 96. The amplifier 96 amplifies the transmission signal and supplies it to the circulator 92. The circulator 92 outputs a transmission signal to the transmission / reception antenna 91.

  The wireless communication terminal 15 in the communication area 1 wirelessly communicates with the base station 11 via the leaky transmission path 12 through the wireless channel CH1. On the other hand, the wireless communication terminal 35 in the communication area 3 wirelessly communicates with the base station 31 via the leaky transmission path 32 on the wireless channel CH1. The wireless communication terminal 15 in the communication area 1 may receive a transmission radio wave from the wireless communication terminal 35 using the same wireless channel as indicated by a dotted arrow A1 in the figure. This transmission radio wave becomes an interference wave.

  The wireless communication terminal 15 that has received the transmission radio wave from the wireless communication terminal 35 controls the second wireless communication unit 90 with the control unit 100, and detects that the wireless communication terminal 35 is using the same channel. Send a notification signal and request the other party to reduce the transmission power. The wireless communication terminal 15 also communicates with the base station 11 with a reduced transmission power because its own transmission radio wave also becomes an interference wave with the wireless communication terminal 35.

The wireless communication terminal 35 receives a signal from the wireless communication terminal 15 using the second wireless communication unit 90, and communicates with the base station 31 by reducing its own transmission power based on a request from the wireless communication terminal 15. To do.
In this way, when an interference wave is received from a wireless communication terminal in another communication area using the same channel, the transmission power of the other wireless communication terminal is requested to be reduced while the own transmission power is reduced. Since the transmission output is lowered, radio wave interference with a wireless communication terminal using the same channel in different communication areas can be prevented as much as possible.

  In addition, the wireless communication terminal 15 performs wireless communication with the base station 11 through the wireless channel CH1, and at this time, the transmission radio wave from the wireless communication terminal existing in another communication area using the adjacent channel is received as an interference wave. There is a case. For example, there is a case where a transmission radio wave is received as an interference wave as indicated by a dotted arrow B1 in the figure from the radio communication terminal 45 in the communication area 4 that communicates with the base station 41 by radio channel CH2.

  Therefore, the radio communication terminal 15 monitors the radio wave condition of the adjacent channel CH2, and when receiving the radio wave transmitted from the radio communication terminal 45, the radio communication terminal 15 uses the second radio communication unit 90 to adjoin the radio communication terminal 45. The channel CH2 is used to transmit a signal notifying the presence of the user using the adjacent channel, and the other party is requested to reduce the transmission power. The wireless communication terminal 15 also communicates with the base station 11 with its transmission power lowered because its own transmission radio wave also becomes an interference wave with the wireless communication terminal 45.

The wireless communication terminal 45 receives a signal from the wireless communication terminal 15 using the second wireless communication unit 90, and communicates with the base station 41 by reducing its transmission power based on a request from the wireless communication terminal 15. To do.
In this way, when an interference wave is received from a wireless communication terminal in another communication area that uses an adjacent channel, it lowers its own transmission power and requests the other wireless communication terminal to lower the transmission power. Since the transmission output is lowered, radio wave interference with a wireless communication terminal using an adjacent channel in a different communication area can be prevented as much as possible.

(Third embodiment)
In this embodiment, when a radio communication terminal receives a transmission radio wave from a radio communication terminal in another communication area in which radio communication is performed using the same channel or an adjacent channel, the corresponding radio communication terminal is communicated via the base station. A wireless communication system that wirelessly transmits a signal that informs the existence of itself and requests a reduction in transmission power and that reduces the transmission power of the wireless communication system will be described.

  As shown in FIG. 6, a plurality of base stations 103, 104, and 105 are connected to the base station control apparatus 101 via a wired LAN 102 at a predetermined interval. Leakage transmission paths 106, 107, 108 are connected to the base stations 103, 104, 105, respectively. Note that terminators 109, 110, and 111 are connected to the ends of the leaky transmission paths 106, 107, and 108, respectively.

  In the communication area formed by the base station 103, the wireless communication terminal 112 performs wireless communication with the base station 103 via the leaky transmission path 106 via the wireless channel CH 1, and in the communication area formed by the base station 104, the wireless communication terminal 113. Wirelessly communicates with the base station 104 via the leaky transmission path 107 via the radio channel CH2, and in the communication area formed by the base station 105, the radio communication terminal 114 communicates with the base station 105 via the leaky transmission path 108 via the radio channel CH1. Wireless communication. The configuration of each of the wireless communication terminals 112, 113, 114 is the same as that shown in FIG.

  The wireless communication terminal 112 may receive a transmission radio wave from the wireless communication terminal 114 using the same wireless channel as indicated by a dotted arrow A2 in the figure. This transmission radio wave becomes an interference wave. The wireless communication terminal 112 that has received the transmission radio wave from the wireless communication terminal 114 transmits a signal notifying the presence of the user using the same channel to the base station control apparatus 101 via the base station 103. Then, its own transmission power is reduced.

  The base station control apparatus 101 receives a signal from the wireless communication terminal 112 and transmits a signal indicating the presence of the wireless communication terminal 112 to the wireless communication terminal 114 via the base station 105 using the same channel as the base station 103. To do. The wireless communication terminal 114 receives the signal, understands that there is a wireless communication terminal using the same channel in another communication area, and reduces its transmission power.

  In this way, when an interference wave is received from a wireless communication terminal in another communication area using the same channel, the transmission power of the other wireless communication terminal is requested to be reduced while the own transmission power is reduced. Since the transmission power is lowered, it is possible to prevent radio wave interference with radio communication terminals using the same channel in different communication areas as much as possible.

  In addition, the wireless communication terminal 112 performs wireless communication with the base station 103 through the wireless channel CH1, and at this time, the transmission radio wave from the wireless communication terminal existing in another communication area using the adjacent channel is received as an interference wave. There is a case. For example, a transmission radio wave may be received as an interference wave from a wireless communication terminal 113 in another communication area that wirelessly communicates with the base station 104 through the wireless channel CH2 as indicated by a dotted line arrow B2 in the figure.

  Therefore, the radio communication terminal 112 monitors the radio wave condition of the adjacent channel CH2, and when receiving the radio wave transmitted from the radio communication terminal 113, the radio communication terminal 112 uses the adjacent channel to the base station control apparatus 101 via the base station 103. Send a signal to inform you of your presence. Then, its own transmission power is reduced.

  The base station control apparatus 101 receives a signal from the wireless communication terminal 112 and sends a signal indicating the presence of the wireless communication terminal 112 to the wireless communication terminal 113 via the base station 104 using a channel adjacent to the base station 103. Send. The wireless communication terminal 113 receives the signal, understands that there is a wireless communication terminal using an adjacent channel in another communication area, and lowers its own transmission power.

  In this way, when an interference wave is received from a wireless communication terminal in another communication area that uses an adjacent channel, it lowers its own transmission power and requests the other wireless communication terminal to lower the transmission power. Since the transmission output is lowered, radio wave interference with a wireless communication terminal using an adjacent channel in a different communication area can be prevented as much as possible.

(Fourth embodiment)
In this embodiment, when a radio communication terminal receives a transmission radio wave from a radio communication terminal in another communication area in which radio communication is performed using the same channel or an adjacent channel, the base station is requested to increase transmission power. A wireless communication system that wirelessly transmits signals will be described.

  As shown in FIG. 7, in a communication area where a leaky transmission line 116 is connected to the base station 115 and a terminator 117 is connected to the end of the leaky transmission line 116, the radio communication terminal 118 is connected to the base station 115 via the radio channel CH1. Wireless communication is performed via the leaky transmission path 116. At this time, a transmission radio wave from the radio communication terminal 119 existing in another radio area using the same radio channel or an adjacent radio channel becomes an interference wave.

  When the wireless communication terminal 118 receives the transmission radio wave from the wireless communication terminal 119 as indicated by the dotted arrow A3 in the figure, the wireless communication terminal 118 transmits a signal requesting the base station 115 to increase the transmission power. Thereby, the base station 115 increases transmission power.

  Thus, thereafter, the level of the required radio wave from the base station 115 is always higher than the unnecessary radio wave from the radio communication terminal 119, and the radio communication terminal 118 can reliably communicate with the base station 115. As a result, radio wave interference with a wireless communication terminal using the same channel in a different communication area or using an adjacent channel can be prevented as much as possible.

(Fifth embodiment)
In this embodiment, when a radio wave is received from a radio communication terminal in another communication area where the radio communication terminal performs radio communication using the same channel, the transmission power is reduced to the minimum necessary to communicate with the base station. A wireless communication system will be described.

  As shown in FIG. 8, a leaky transmission line 122 is connected to the base station 121, a communication area 124 in which a terminator 123 is connected to the end of the leaky transmission line 122, and a leaky transmission line 126 is connected to the base station 125. A communication area 128 in which a terminator 127 is connected to the end of the leaky transmission line 126 is arranged.

  In the communication area 124, the wireless communication terminal 129 communicates wirelessly with the base station 121 via the leaky transmission path 122 using the wireless channel CH 1, and in the communication area 128, the wireless communication terminal 130 uses the same wireless channel CH 1 as the communication area 124 to Wireless communication is performed via the station 125 and the leakage transmission path 126.

  Under such an environment, in the wireless communication terminal 129 in the communication area 124, the transmission radio wave from the wireless communication terminal 130 in the communication area 128 becomes an interference wave. On the contrary, in the wireless communication terminal 130 in the communication area 128, the transmission radio wave from the wireless communication terminal 129 in the communication area 124 becomes an interference wave.

  Therefore, when the radio communication terminal 129 in the communication area 124 receives the transmission radio wave from the radio communication terminal 130 in the communication area 128, the radio communication terminal 129 reduces its own transmission power to the minimum necessary transmission power capable of communicating with the base station 121. In addition, when the radio communication terminal 130 in the communication area 128 receives the transmission radio wave from the radio communication terminal 129 in the communication area 124, the radio communication terminal 130 reduces its own transmission power to the minimum necessary transmission power capable of communicating with the base station 125.

  In this way, the wireless communication terminal 129 in the communication area 124 and the wireless communication terminal 130 in the communication area 128 communicate with each other by reducing the transmission power to the minimum transmission power necessary to communicate with the base station. It can be reduced as much as possible.

(Sixth embodiment)
This embodiment describes a wireless communication system in which an antenna of a wireless communication terminal is provided with a radio wave attenuation cover. The configuration of the communication area is the same as that of the fifth embodiment described above.

  FIG. 9 is a block diagram showing the configuration of a wireless communication terminal used in this wireless communication system. Like FIG. 2 described above, the circulator 72 supplies the reception signal received by the transmission / reception antenna 71 to the reception amplifier 73. 73 amplifies the received signal and supplies it to the receiver 74. The receiver 74 demodulates the received signal and supplies it to the controller 75.

  The controller 75 controls the transmitter 76 together with the receiver 74. The transmitter 76 modulates the transmission signal and supplies the modulated transmission signal to the transmission amplifier 77. The amplifier 77 amplifies the transmission signal and supplies it to the circulator 72. The circulator 72 outputs a transmission signal to the transmission / reception antenna 71. The transmission / reception antenna 71 is detachably provided with a radio wave attenuation cover 78 for suppressing transmission power.

  In such a configuration, as shown in FIG. 10A, in addition to the communication area 124, the wireless communication terminal 131 performs leak transmission in an environment where there is no other communication area using the same wireless channel nearby. When radio communication is performed with the base station 121 via the path 122, radio wave interference does not occur. At this time, the radio communication terminal 131 performs communication with the radio wave attenuation cover 78 removed.

  However, as shown in FIG. 10 (b), when there is another communication area 128 that uses the same wireless channel near the communication area 124, there is a high possibility that radio wave interference will occur. The wireless communication terminal 131 in the area 124 communicates with the base station 121 by attaching the radio wave attenuation cover 78 to the transmission / reception antenna 71. The wireless communication terminal 132 in the communication area 128 also communicates with the base station 125 by attaching the radio wave attenuation cover 78 to the transmission / reception antenna 71.

  In this way, the wireless communication terminal 131 in the communication area 124 and the wireless communication terminal 132 in the communication area 128 communicate with the base station by attenuating each other's transmission power with the radio wave attenuation cover 78, so that mutual radio wave interference can be reduced as much as possible. Can do.

(Seventh embodiment)
This embodiment describes a wireless communication system in which directivity is given to an antenna of a wireless communication terminal.
As shown in FIG. 11, leaky transmission lines 143 and 144 are laid above the two tables 141 and 142 arranged close to each other so that the slots S face downward.

  The leaky transmission line 143 has one end connected to the base station 145 and the other end connected to the terminator 146. The leaky transmission line 144 has one end connected to the base station 147 and the other end connected to the terminator 148. Wireless communication terminals 149 and 150 that wirelessly communicate with the base stations 145 and 147 via leaky transmission paths 143 and 144 are placed on the tables 141 and 142, respectively.

  The wireless communication terminal 149 has a directivity D1 facing upward so as to reliably communicate with the leaky transmission line 143. Further, the wireless communication terminal 150 has a directivity D2 facing upward so as to reliably communicate with the leaky transmission line 144.

  In such a configuration, the radio wave from the radio communication terminal 149 reaches the leaky transmission line 143 connected to the base station 145 that performs communication, but the radio communication terminal 150 used on the adjacent table 142. It will not reach. Similarly, the radio wave from the radio communication terminal 150 reaches the leaky transmission path 144 connected to the base station 147 that performs communication, but does not reach the radio communication terminal 149 used on the adjacent table 141. . Accordingly, the transmission radio waves do not become mutual interference waves, and the wireless communication terminals 149 and 150 can reliably communicate with the base stations 145 and 147, respectively.

(Eighth embodiment)
This embodiment also describes a wireless communication system in which directivity is given to an antenna of a wireless communication terminal.
As shown in FIG. 12, leaky transmission lines 151 and 152 are laid on the back side of the two tables 141 and 142 so that the slots S face upward. Although not shown, a base station is connected to one end of the leaky transmission lines 151 and 152, and a terminator is connected to the other end.

  On the tables 141 and 142, wireless communication terminals 153 and 154 for wirelessly communicating with the base station via leaky transmission paths 151 and 152 are placed. The wireless communication terminal 153 has a directivity D3 directed downward so as to reliably communicate with the leaky transmission path 151. The wireless communication terminal 154 has a directivity D4 facing upward so as to communicate with the leaky transmission path 152 reliably.

  In such a configuration, the radio wave from the wireless communication terminal 153 reaches the leaky transmission path 151 but does not reach the wireless communication terminal 154 used on the adjacent table 142. Similarly, the radio wave from the wireless communication terminal 154 reaches the leaky transmission path 152 but does not reach the wireless communication terminal 153 used on the adjacent table 141. Accordingly, the transmission radio waves do not become mutual interference waves, and the wireless communication terminals 153 and 155 can reliably communicate with the respective base stations.

  As the antennas of the wireless communication terminals 149 and 150 in the seventh embodiment and the antennas of the wireless communication terminals 153 and 154 in the eighth embodiment, for example, a plurality of antenna elements are arranged, and If an array antenna that configures directivity by changing the feed phase and the feed amplitude is used, the directivity can be changed by controlling the amplitude and phase.

  That is, when used as the wireless communication terminals 149 and 150 in the seventh embodiment, the directivity is directed upward by controlling the amplitude and phase, and used as the wireless communication terminals 153 and 154 in the eighth embodiment. When doing so, directivity is directed downward by controlling the amplitude and phase. In this way, one wireless communication terminal can be shared in the case of the seventh embodiment and the case of the eighth embodiment.

  Further, without using an array antenna, a transmission / reception antenna having directivity above and a transmission / reception antenna having directivity below may be provided and switched. That is, as shown in FIG. 13, the common contact c of the switch 79 is connected to the circulator 72 of the wireless communication terminal 160. A transmission / reception antenna 80 having directivity is connected to one contact point a of the switch 79, and a transmission / reception antenna 81 having directivity is connected to the other contact point b.

  As described above, even when the wireless communication terminal 160 having the two transmission / reception antennas 80 and 81 is used, when the wireless communication terminal 160 is used as the wireless communication terminal in the seventh embodiment, the common contact c of the switch 79 is changed to the contact a. When the transmitting / receiving antenna 80 having the directivity connected upward is used and used as the wireless communication terminal in the eighth embodiment, the common contact c of the switch 79 is connected to the contact b and the directivity downward. Is used. In this way, one wireless communication terminal can be shared in the case of the seventh embodiment and the case of the eighth embodiment.

The figure which shows the structure of the radio | wireless communications system which concerns on the 1st Embodiment of this invention. The block diagram which shows the structure of the radio | wireless communication terminal used in the embodiment. The figure which shows the memory | storage information of the memory | storage part of the radio | wireless communication terminal used in the embodiment. The figure which shows the structure of the radio | wireless communications system which concerns on the 2nd Embodiment of this invention. The block diagram which shows the structure of the radio | wireless communication terminal used in the embodiment. The figure which shows the structure of the radio | wireless communications system which concerns on the 3rd Embodiment of this invention. The figure which shows the structure of the radio | wireless communications system which concerns on the 4th Embodiment of this invention. The figure which shows the structure of the radio | wireless communications system which concerns on the 5th Embodiment of this invention. The block diagram which shows the structure of the radio | wireless communication terminal which concerns on the 6th Embodiment of this invention. The figure for demonstrating the operation | movement of the embodiment. The figure which shows the structure of the radio | wireless communications system which concerns on the 7th Embodiment of this invention. The figure which shows the structure of the radio | wireless communications system which concerns on the 8th Embodiment of this invention. The block diagram which shows the modification of the radio | wireless communication terminal used in FIG.11 and FIG.12.

Explanation of symbols

  1-6 ... Communication area 11, 21, 31, 41, 51, 61 ... Base station, 12, 22, 32, 42, 52, 62 ... Leakage transmission path, 14, 24, 34, 44, 54, 64 ... Wireless communication terminal, 75... Control unit, 78.

Claims (2)

In a wireless LAN system in which a plurality of communication areas formed by connecting a leaky transmission path to a base station are arranged, and a wireless communication terminal performs radio communication with the base station via the leaky transmission path in each communication area,
A channel for wireless communication is allocated to each base station in each communication area,
When the radio communication terminal receives a transmission radio wave from a radio communication terminal in another communication area that performs radio communication using the same channel, the radio communication terminal requests the radio communication terminal in the other communication area to reduce transmission power. In addition, the wireless LAN system is characterized in that when performing wireless communication with a base station in a communication area in which the wireless device exists, the transmission power is reduced to the minimum necessary level. The wireless LAN system according to claim 1, wherein the wireless communication terminal decreases its transmission power when receiving a signal requesting a decrease in transmission power from a wireless communication terminal in another communication area.

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