JP5248415B2 - Wireless LAN communication system - Google Patents

Description

  The present invention relates to a wireless LAN communication system, and in particular, a wireless LAN master unit is installed in a building specified as a master station, connected to an information center via a broadband line, and connected to a plurality of buildings around the master station. A wireless LAN in which a slave unit is installed as a slave station of a wireless LAN, a broadband line connecting the master station and the information center is shared by a plurality of slave stations, and the master station and the slave station form a network to perform remote monitoring The present invention relates to a communication system.

  FIG. 5 shows a wireless LAN communication system in which a master station and a slave station form a network and perform remote monitoring. A master station 102, which is a specific building where a wireless LAN master device 107 is installed, is connected to an information center 104 via a wired communication line 105 such as a telephone line. A plurality of slave stations 103a, 103b, and 103c in which wireless LAN slave devices 108a, 108b, and 108c around the master station 102 are installed are connected to the master station 102 by wireless communication lines 106a, 106b, and 106c. With this configuration, a wireless LAN communication system 100 is constructed in which the broadband line 105 between the parent device 107 and the communication control device 109 of the information center 104 is shared by a plurality of slave stations 103a, 103b, and 103c to perform remote monitoring.

  The wireless LAN communication system 100 is used, for example, for building facility management work. Then, for example, a large amount of image data such as video taken by a video camera in the elevator is transmitted from each building to the information center 104. In addition, for example, operating conditions and abnormality information of elevators, escalators, water supply / drainage facilities, air conditioning facilities, etc., which are equipment in the building, are transmitted from the slave units 108 of each building to the information center 104.

FIG. 6 shows data communication from the slave stations 103a and 103b to the master station 102 in time series. As shown in FIG. 6, the slave station 103b is closer to the master station 102 and has a shorter communication distance than the slave station 103a. For example, if the transmission of the data A at time _{t 1} from the slave station 103a to the master station 102 is started, to the time _{t 2} from the slave station 103b and the master station 102 is data B is transmitted by the wireless communication line 106b . At this time, the packet sonde by transmission from transmission to the master station 102 is the slave station 103b from the slave station 103a, there is a case where communication trouble occurs so-called IP packets dropped.

  This is because the slave units 108a, 108b, and 108c of all the slave stations 103a, 103b, and 103 in wireless communication use a carrier wave having the same frequency regardless of the communication distance from the master station 102. This is because the radio wave from 103b is so strong that a “far-far problem” occurs in which the signal from the slave station 103a farther from the master station 102 is not recognized by the master unit 107 of the master station 102.

  On the other hand, mobile phone base stations represented by the WCDMA system, by using adaptive transmission power control having a function to control transmission power, weakens the power transmission capability of mobile phones in the vicinity of the base station and is far from the base station. This “far-far problem” is dealt with by strengthening the power transmission capacity of mobile phones.

JP-A-2005-294943

  As described above, the wireless LAN slave unit A having a poor radio wave state installed far from the building where the wireless LAN base unit is installed, and the radio wave state installed in the vicinity of the building where the wireless LAN base unit is installed. Even if the wireless LAN handset B with good wireless LAN tries to perform data communication, the communication data of the handset A having a poor radio wave condition may cause a communication failure. Further, when the slave unit B having a good radio wave state performs data communication with the base unit of the wireless LAN, the slave unit A having a poor radio wave state performs data communication with the base unit of the wireless LAN. There may be a problem with communication with the base unit.

  In general, commercially available outdoor wireless LAN devices are not equipped with the above-described function of controlling transmission power. Commercially available outdoor wireless LAN devices are sold under the appropriate skill mark from the Ministry of Internal Affairs and Communications, and if adaptive transmission power control is added later, there is a risk of unauthorized products. Therefore, when using a commercially available outdoor wireless LAN device, the “far / near problem” cannot be solved by controlling the transmission power.

  An object of the present application is to provide a wireless LAN communication system that solves such a problem and enables both a slave unit having a good radio wave condition and a slave unit having a poor radio wave condition to perform data communication with the master unit by wireless LAN to the same extent. is there.

  In order to achieve the above object, a wireless LAN communication system according to the present invention has a wireless LAN master unit installed in a building identified as a master station and connected to an information center via a broadband line. A wireless LAN communication system in which a slave unit is installed as a slave station of a wireless LAN in a plurality of buildings, and a broadband line connecting the master station and the information center is shared by the slave stations to perform remote monitoring. The slave unit includes a communication data storage unit that stores communication data to be transmitted to the master unit, a priority storage unit that stores a slave unit number of the slave unit, and a priority set for the slave unit, and a master unit. Communication control means for transmitting a communication request signal including a priority to the base unit and transmitting stored communication data to the base unit when the communication permission signal is received from the base unit. The priority sent from Priority storage means for storing in association with each other, and when receiving a communication request signal from a plurality of slave units, priority order determination unit for determining priority by comparing the priority transmitted from each slave unit, A communication control means for receiving a communication request signal from the slave unit and transmitting any one of a communication permission signal, a communication non-permission signal, or a communication interruption signal to the slave unit. When one slave unit receives a communication request signal from another slave unit during data communication, it transmits a communication permission signal to the communication control means of the slave unit having a high priority, and the priority is low. A communication non-permission signal or a communication interruption signal is transmitted to the communication control means of the slave unit.

  With the above configuration, the wireless LAN communication system sets priority for each slave unit, and even if a communication request signal is transmitted from the communication control means of a plurality of slave units, the slave unit with higher priority gives priority to communication data. Can be sent. Further, even when a slave device with a low priority is transmitting communication data, the communication data can be preferentially transmitted by switching to a slave device with a higher priority. As a result, the slave unit having a good radio wave condition and the slave unit having a poor radio wave condition can perform data communication with the master unit to the same extent by setting a priority.

  In addition, the wireless LAN communication system includes priority setting means for setting a higher priority to each child device in order of increasing communication distance between each child station and the parent station, and a priority storage means for each child device. Preferably stores the priority set by the priority setting means. As a result, it is possible to prevent the occurrence of a communication failure called so-called IP packet drop due to the communication distance from the parent device.

  Further, the wireless LAN communication system determines the priority according to the urgency of the communication data stored in the communication data storage means, and if the slave is higher than the priority set for the slave, It is preferable to provide priority judgment means for changing the priority only for the communication data and transmitting the communication request signal to the communication control means of the machine. Thereby, when transmitting communication data with a high degree of urgency, the priority can be changed and transmitted regardless of the set priority.

  In addition, when the communication distance between the master station and the master station is approximately the same, the wireless LAN communication system initializes the priority of the slave equipment at random and sets each slave device after a predetermined period of time. It is preferable that random priority setting means for randomly changing the priority of the machine again is provided, and the priority storage means of each child machine stores the initially set priority and updates when the priority is changed. . Accordingly, even when the communication distance between the slave station and the master station is approximately the same, the priority can be set more fairly by setting the priority randomly and updating it after a predetermined period.

  Further, in the wireless LAN communication system, when the communication control unit of the slave unit receives a communication interruption signal from the communication control unit of the master unit, the transmission of the communication data is interrupted, and the untransmitted communication data is again stored in the communication data storage unit. It is preferable to store it. Thereby, even if transmission of communication data is interrupted, untransmitted communication data can be transmitted again without any problem.

  Further, in the wireless LAN communication system, when the communication control means of the slave unit receives a communication non-permission signal from the master unit, a communication request signal including the priority is again transmitted to the master unit after a predetermined time has elapsed. It is preferable to do. Thereby, even if a subunit | mobile_unit receives a communication non-permission signal, it can acquire the opportunity of transmission again.

  In the wireless LAN communication system, it is preferable that the communication control unit of the slave unit transmits a communication end signal to the communication control unit of the master unit when the data communication is completed. Thereby, the communication control means of the parent device can be prepared for a new communication request signal from another child device.

  In the wireless LAN communication system, it is preferable that the communication data transmitted to the master unit includes video data captured by a video camera or a monitor in the building. Thereby, the slave unit can efficiently transmit video data having a large amount of data to the master unit.

  Further, in the wireless LAN communication system, when the slave unit has communication data stored in the communication data storage means being a voice or video of a passenger confined in a room or an elevator car, the slave unit has the highest degree of urgency. It is preferable to set. Thereby, in an emergency such as a disaster, the highest priority can be set regardless of the preset priority.

  As described above, according to the wireless LAN communication system according to the present invention, the wireless LAN communication in which both the slave unit having a good radio wave condition and the slave unit having a poor radio wave condition can perform data communication with the parent machine to the same extent. A system can be provided.

1 is a block diagram showing a schematic configuration of one embodiment of a wireless LAN communication system according to the present invention. It is explanatory drawing which shows the wireless LAN communication system which a parent station and a slave station form a network, and performs remote monitoring. It is explanatory drawing which shows one example of the data communication from a child station to a parent station in time series. It is explanatory drawing which shows the other example of the data communication from a child station to a parent station in time series. It is explanatory drawing which shows the conventional wireless LAN communication system which a parent station and a slave station form a network, and performs remote monitoring. It is explanatory drawing which shows the data communication from the conventional slave station to a parent station in time series.

  Hereinafter, an embodiment of a wireless LAN communication system according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of one embodiment of a wireless LAN communication system according to the invention. FIG. 2 shows a wireless LAN communication system in which a master station and a slave station form a network and perform remote monitoring. In the wireless LAN communication system 1, a wireless LAN base unit 7 is installed in a building identified as the master station 2 and connected to the communication control device 9 of the information center 4 via the broadband line 5. In addition, slave units 8a, 8b, and 8c are installed as wireless LAN slave stations 3a, 3b, and 3c in a plurality of buildings around the master station 2. The parent device 7 and the child devices 8a, 8b, and 8c are connected via the wireless communication line 6. Then, the broadband line 5 connecting the master station 2 and the information center 4 is shared by the plurality of slave stations 3a, 3b, 3c to perform remote monitoring.

  The slave unit 8a of the slave station 3a includes a communication data storage unit 10, a slave unit priority storage unit 11, a slave unit communication control unit 12, and a priority determination unit 17. This child device 8a is connected to the equipment 23 in the building, the video camera 19 or the monitor 20 via a remote equipment monitoring device 21 provided in the building. In the present embodiment, the slave unit 8 is described as an example of three slave units 8a, 8b, 8c, but the number of the slave units 8 is not limited to this. In addition, since it is the structure similar to the subunit | mobile_unit 8a also about the subunit | mobile_unit 8b and the subunit | mobile_unit 8c, the description is abbreviate | omitted.

  The base unit 7 of the base station 2 includes a base unit priority storage unit 13, a priority order determination unit 14, a base unit communication control unit 15, a priority setting unit 16, and a random priority setting unit 18. The base unit communication control means 15 of the base unit 7 is connected to the communication control device 9 of the information center 4 via the broadband line 5, and communication data is transmitted to the information center 4.

  The communication data storage means 10 of the child device 8 stores communication data to be transmitted to the parent device 7. This communication data is data relating to the equipment 23 in the building collected via the remote equipment monitoring device 21 and includes video data taken by the video camera 19 and the monitor 20 in the building. The slave unit priority storage means 11 stores a slave unit number set for the slave unit 8 and a priority set later for the slave unit 8. Then, when communication data to be transmitted to the parent device 7 is generated, the child device communication control means 12 sends a communication request signal with the priority and the child device number stored in the child device priority storage means 11 to the parent device 7. A call is transmitted via the wireless communication line 6. Further, when receiving the communication permission signal from the parent device 7 via the wireless communication line 6, the child device communication control means 12 transmits the stored communication data to the parent device 7.

  The parent device priority storage means 13 stores the priority added to the communication request signal transmitted from the child devices 8a, 8b, and 8c in association with the child device number. When receiving the communication request signal from the plurality of slave units 8a, 8b, 8c, the priority order determination unit 14 compares the priority levels transmitted from the respective slave units 8a, 8b, 8c to determine the priority order. . As for this priority, the priority setting means 16 sets a higher priority to each of the slave units 8a, 8b, and 8c in order of increasing communication distance between each of the slave stations 3a, 3b, and 3c and the master station 2. For example, in the network shown in FIG. 2, since the communication distance (La) between the child device 8a and the parent station 2 is the longest, the first priority is given to the child device 8a, and then the communication distance (Lc). The second-priority priority is given to the remote handset 8c having a long communication distance, and the third-priority priority is given to the handset 8b having the shortest communication distance (Lb) closest to the parent handset 7. And the subunit | mobile_unit priority memory | storage means 11 of each subunit | mobile_unit 8a, 8b, 8c memorize | stores the priority which the priority setting means 16 set.

  FIG. 3 shows one example of data communication from the slave stations 3a and 3b to the master station 2 in time series. The base unit communication control means 15 receives the communication request signal from the handset 8a, 8b, 8c, and is one of a communication permission signal, a communication non-permission signal, or a communication interruption signal for the handset 8a, 8b, 8c. Send. When receiving the communication request signal from the slave unit communication control unit 12 of the other slave unit 8b while receiving the communication data from one slave unit 8a, the master unit communication control unit 15 receives the priority order determining unit 14 Transmits a communication permission signal to the slave unit communication control means 12 of the slave unit 8 having a higher priority determined, and transmits a communication disapproval signal or a communication interruption signal to the slave unit communication control unit 12 of the slave unit 8 having a lower priority. To do.

That is, as shown in FIG. 3, originated communication request signal from the slave unit 8b of the child station 3b at time t ₁ the master unit 7 of the master station 2, the communication permission signal to the base unit 7 slave unit 8b Sent. Data B is transmitted from the slave unit 8b by this communication permission signal. During transmission of the data B from the slave unit 8b, a communication request signal is transmitted to the t ₂ time from the slave unit 8a of the child station 3a to the base unit 7 of the master station 2. In this case, the master communication control means 15 follows the order determined by the priority order determination means 14 of the master unit 7, that is, the third priority for the slave unit 8b and the first priority for the slave unit 8a. . That is, for the slave unit 8b, and transmits a communication interruption signal t ₃ time, for the slave unit 8a, transmits the communication permission signal at the same time. When the slave unit communication control unit 12 of the slave unit 8 b receives the communication interruption signal from the master unit communication control unit 15, the slave unit communication control unit 12 interrupts the transmission of the communication data and causes the communication data storage unit 10 to store the untransmitted communication data again.

Further, the slave unit communication control means of the slave unit 8b 12 includes upon receiving a communication interruption signal from the master unit communication control means 15, to t ₅ the time a predetermined time has elapsed, again priority to the base unit 7 A communication request signal is transmitted. On the other hand, the slave unit communication control unit 12 of the slave unit 8a receives the communication permission signal from the base unit communication control means 15 starts the transmission of the communication data A t ₄ time. The slave unit communication control means 12 of the slave unit 8 a transmits a communication end signal to the master unit communication control unit 15 when the transmission of the communication data is completed. When the data communication of the child device 8a is finished, the parent device communication control means 15 transmits a communication permission signal to the child device 8b. In this case, the base unit communication control means 15 may transmit a communication permission signal to the interrupted slave unit 8b by the communication end signal of the slave unit 8a without waiting for the communication request signal from the slave unit 8b. .

FIG. 4 shows another example of data communication from the slave stations 3a and 3b to the master station 2 in time series. Communication request signals at time t ₁ from the slave unit 8a of the child station 3a to the base unit 7 of the master station 2 is transmitted, the communication permission signal is transmitted to the base unit 7 slave unit 8a. Data A is transmitted from the slave unit 8a by this communication permission signal. During transmission of the data A from the slave unit 8a, a communication request signal is transmitted to the t ₂ time from the slave unit 8b of the child station 3b to the base unit 7 of the master station 2. In this case, the master communication control means 15 follows the order determined by the priority order determination means 14 of the master unit 7, that is, the third priority for the slave unit 8b and the first priority for the slave unit 8a. . That is, for the slave unit 8b, and transmits the communication disable signal to t ₃ time, for the slave unit 8a, is continued as the data communication.

Further, the slave unit communication control unit 12 of the slave unit 8b receives the communication disable signal from the main unit communication control means 15, to t ₅ the time a predetermined time has elapsed, again priority to the base unit 7 A communication request signal including the above is transmitted. On the other hand, the slave unit communication control unit 12 of the slave unit 8a transmits a communication end signal to the master unit communication control unit 15 when the transmission of the communication data is completed. When the data communication of the child device 8a is finished, the parent device communication control means 15 transmits a communication permission signal to the child device 8b. In this case, the base unit communication control means 15 may transmit a communication permission signal to the standby slave unit 8b by the communication end signal of the slave unit 8a without waiting for the communication request signal from the slave unit 8b. .

  When the communication distances between the plurality of slave stations 3 and the master station 2 are approximately the same, the random priority setting means 18 of the master unit 7 randomly sets the priority of the slave units 8 at a predetermined level. After the elapse of the period, the priority of each slave unit 8 is randomly changed again. And the subunit | mobile_unit priority memory | storage means 11 of each subunit | mobile_unit 8 memorize | stores the initially set priority, and will be updated if a priority is changed. For example, when the communication distance (La) of the child device 8a and the communication distance (Lc) of the child device 8c in FIG. 2 can be regarded as substantially the same, the random priority setting unit 18 sets the child device 8a and the child device 8c. Are randomly set regardless of the communication distance, for example, the second priority is given to the slave unit 8a, and the first priority is given to the slave unit 8c. Then, for example, the priority of each of the slave units 8a and 8c is randomly changed again after a predetermined period such as one week or one month has elapsed. Thereby, in the long term, the priority of each of the slave units 8a and 8c is imparted fairly.

  The priority determination unit 17 of the child device 8 determines the priority according to the urgency of the communication data stored in the communication data storage unit 10, and when the priority is higher than the priority set for the child device 8, The slave unit communication control means 12 is caused to change the priority only for the communication data and transmit a communication request signal. For example, if the communication data is the voice or video of passengers confined in the room or elevator car, the urgency should be the highest, and the response will be delayed at a preset priority. There is. In this case, in any case of FIG. 3 and FIG. 4, the priority order determination means 14 transmits a communication permission signal to the slave unit 8 that requests data communication with a high degree of urgency according to the priority changed to a higher level. To do. And a communication interruption signal is transmitted with respect to the subunit | mobile_unit 8 in communication as shown in FIG.

  1,100 Wireless LAN communication system, 2,102 Master station, 3a, 3b, 3c, 103a, 103b, 103c Slave station, 4,104 Information center, 5,105 Wired communication line (broadband line), 6, 106a, b Wireless communication line, 7, 107 master unit, 8, 108 slave unit, 9, 109 communication control device, 10 communication data storage unit, 11 slave unit priority storage unit, 12 slave unit communication control unit, 13 master unit priority storage Means 14 priority order determining means 15 master communication control means 16 priority setting means 17 priority judging means 18 random priority setting means 19 video camera 20 monitor 21 remote equipment monitoring device 23 equipment .

Claims (10)

A wireless LAN master unit is installed in the building identified as the master station, connected to the information center via a broadband line, and slave units are installed as wireless LAN slave stations in a plurality of buildings around the master station. A wireless LAN communication system for performing remote monitoring by sharing a broadband line connecting a station and an information center with a plurality of slave stations,
The slave unit is
Communication data storage means for storing communication data to be transmitted to the master unit;
Priority storage means for storing the slave unit number of the slave unit and the priority set for the slave unit;
A communication control means for transmitting a communication request signal including a priority to the parent device, and transmitting stored communication data to the parent device when a communication permission signal is received from the parent device;
The master unit of the master station
Priority storage means for storing the priority transmitted from the slave unit in association with the slave unit number;
When receiving communication request signals from a plurality of slave units, priority order determining means for determining the priority order by comparing the priorities transmitted from each slave unit;
A communication control means for receiving a communication request signal from the slave unit and transmitting either a communication permission signal, a communication non-permission signal, or a communication interruption signal to the slave unit;
A priority setting means for setting a high priority to each slave unit in order of increasing communication distance between each slave station and the master station ,
The priority storage means of each slave unit stores the priority set by the priority setting means,
When one slave unit receives a communication request signal from another slave unit during data communication, the master unit's communication control unit sends a communication permission signal to the communication control unit of the slave unit having the determined high priority. A wireless LAN communication system characterized by transmitting and transmitting a communication non-permission signal or a communication interruption signal to a communication control means of a slave unit having a low priority. A wireless LAN master unit is installed in the building identified as the master station, connected to the information center via a broadband line, and slave units are installed as wireless LAN slave stations in a plurality of buildings around the master station. A wireless LAN communication system for performing remote monitoring by sharing a broadband line connecting a station and an information center with a plurality of slave stations,
The slave unit is
Communication data storage means for storing communication data to be transmitted to the master unit;
Priority storage means for storing the slave unit number of the slave unit and the priority set for the slave unit;
A communication control means for transmitting a communication request signal including a priority to the parent device, and transmitting stored communication data to the parent device when receiving a communication permission signal from the parent device;
The priority is determined according to the urgency of the communication data stored in the communication data storage means, and if the priority is higher than the priority set in the slave unit, the communication data is sent to the communication control unit of the slave unit. Priority determining means for changing the priority as much as possible and transmitting a communication request signal ,
The master unit of the master station
Priority storage means for storing the priority transmitted from the slave unit in association with the slave unit number;
When receiving communication request signals from a plurality of slave units, priority order determining means for determining the priority order by comparing the priorities transmitted from each slave unit;
Communication control means for receiving a communication request signal from the slave unit and transmitting either a communication permission signal, a communication non-permission signal, or a communication interruption signal to the slave unit,
When one slave unit receives a communication request signal from another slave unit during data communication, the master unit's communication control unit sends a communication permission signal to the communication control unit of the slave unit having the determined high priority. A wireless LAN communication system characterized by transmitting and transmitting a communication non-permission signal or a communication interruption signal to a communication control means of a slave unit having a low priority. A wireless LAN master unit is installed in the building identified as the master station, connected to the information center via a broadband line, and slave units are installed as wireless LAN slave stations in a plurality of buildings around the master station. A wireless LAN communication system for performing remote monitoring by sharing a broadband line connecting a station and an information center with a plurality of slave stations,
The slave unit is
Communication data storage means for storing communication data to be transmitted to the master unit;
Priority storage means for storing the slave unit number of the slave unit and the priority set for the slave unit;
A communication control means for transmitting a communication request signal including a priority to the parent device, and transmitting stored communication data to the parent device when a communication permission signal is received from the parent device;
The master unit of the master station
Priority storage means for storing the priority transmitted from the slave unit in association with the slave unit number;
When receiving communication request signals from a plurality of slave units, priority order determining means for determining the priority order by comparing the priorities transmitted from each slave unit;
A communication control means for receiving a communication request signal from the slave unit and transmitting either a communication permission signal, a communication non-permission signal, or a communication interruption signal to the slave unit;
When the communication distance between the slave station and the master station is approximately the same, the priority of those slave units is randomly initialized, and the priority of each slave unit is randomly changed again after a predetermined period of time. And a degree setting means ,
The priority storage means of each slave unit stores the preset priority, and updates when the priority is changed,
When one slave unit receives a communication request signal from another slave unit during data communication, the master unit's communication control unit sends a communication permission signal to the communication control unit of the slave unit having the determined high priority. A wireless LAN communication system characterized by transmitting and transmitting a communication non-permission signal or a communication interruption signal to a communication control means of a slave unit having a low priority. The wireless LAN communication system according to claim 1 or 3 , wherein the slave unit determines priority according to the urgency level of the communication data stored in the communication data storage unit, and the priority set in the slave unit If there is a higher priority, the wireless LAN communication system is characterized by comprising priority determination means for changing the priority of only the communication data to the communication control means of the slave unit and transmitting a communication request signal. The wireless LAN communication system according to claim 1 or 2, wherein when the communication distance between the slave station and the master station is approximately the same, the master unit randomly sets priority of the slave units. And a random priority setting means for randomly changing the priority of each slave unit again after a predetermined period of time, and the priority storage means of each slave unit stores the preset priority and the priority is changed. A wireless LAN communication system which is updated when it is updated. The wireless LAN communication system according to any one of claims 1 to 5 , wherein the communication control unit of the slave unit interrupts transmission of communication data upon receiving a communication interruption signal from the communication control unit of the master unit, A wireless LAN communication system, wherein untransmitted communication data is stored again in a communication data storage means. The wireless LAN communication system according to any one of claims 1 to 6 , wherein when the communication control means of the slave unit receives a communication non-permission signal from the master unit, the slave unit communicates with the master unit after a predetermined time elapses. A wireless LAN communication system, wherein a communication request signal including priority is transmitted again. A wireless LAN communication system according to any one of claims 1 to 7, the communication control means of the slave unit, when the data communication is completed, sending a communication termination signal to the communication control means of the master unit A wireless LAN communication system. A wireless LAN communication system according to any one of claims 1 to 8, the communication data to be transmitted to the master unit, characterized in that the video cameras and monitors in the building include video data photographed Wireless LAN communication system. The wireless LAN communication system according to any one of claims 4 to 9 , wherein the slave unit is configured such that the communication data stored in the communication data storage unit is a voice of a passenger in a room or an elevator car or A wireless LAN communication system characterized in that, when it is a video, the highest urgency level is set.

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