JP2009021652A - Radio communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication system which has short delays and small delay fluctuations, by controlling connection relation between radio base stations and radio terminals, and to prevent each radio base station from handling data to a plurality of radio terminals belonging to a different class. <P>SOLUTION: The radio communication system which provides content services, including video or audio, makes a transmission server 101 store arrangement information on respective radio base stations 102 to 105 and corresponding classes of and arrangement information on respective radio terminals, and determines the connection relationship between the radio base stations and radio terminals, based on these pieces of information. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wireless communication system, and more particularly to a wireless communication system that transmits and receives data including a video signal or an audio signal over a wireless network.

  Currently, for example, passenger aircraft are equipped with an information system that provides passengers with various information for emergency use and entertainment use.

  This information system is configured as an information distribution system including a transmission facility that stores and distributes information sources, and a reception facility that is connected to the transmission facility via a wired or wireless transmission path.

  In addition, when a wireless transmission path is used as a transmission path between a transmission facility and a reception facility, the transmission facility includes a plurality of wireless base stations, and information distribution is achieved by connecting a plurality of terminal devices via a wireless network. Configured as a system.

Conventionally, as a communication system that connects such a plurality of radio base stations and radio terminals, there has been one described in Patent Document 1, for example. FIG. 9 shows a configuration of a conventional wireless communication system described in the above-mentioned patent document. In FIG. 9, based on the information unique to each terminal device 504 to 508 stored in the host computer 501 and the installation information of each terminal device 504 to 508, the host computer 501 uses each repeater 502, 503 and each terminal device 504 to 504. By controlling the wireless connection with 508, optimal wireless control between each of the repeaters 502 and 503 and each of the terminal devices 504 to 508 according to the model and situation of the installed terminal devices 504 to 508 is realized.
JP 2000-41043 A

  However, the conventional communication system is assumed to be a POS system or a game field management system, which eliminates unevenness in the amount of data handled by the wireless base station when installing or moving terminal devices, and simplifies wireless connection work. It is an object. It is not assumed that different video and audio services are provided to terminal devices divided into a plurality of classes having different priorities such as first class, business class, and economy class such as IFE in an aircraft. Therefore, in the conventional configuration, terminal devices belonging to different classes are connected to a single repeater, and when distribution data for a specific class is generated, it is affected by traffic to other class terminal devices, In some cases, communication quality deteriorates due to packet loss or delay.

  In addition, since it is necessary to store in advance information unique to all terminal devices in the host computer, it takes time to install the terminal device or replace a faulty terminal.

  Also, in situations where the amount of communication data changes or the state of communication changes depending on the usage status, the host computer optimizes the wireless connection between each repeater and each terminal device periodically or at any time. Communication was interrupted.

  The present invention has been made to solve such a problem, and even when the terminal device is divided into a plurality of classes and provides different video and audio services to each class, the stable communication quality is achieved. An object is to provide a wireless communication system that can be maintained.

  In order to solve the above-described problems, a wireless communication system of the present invention includes a transmission server, a plurality of wireless base stations connected to the transmission server by wire or wirelessly, and a plurality of wireless base stations arranged to be able to transmit and receive to the wireless base station. A wireless communication system for providing a content service including video or audio to a wireless terminal via a wireless base station, wherein the wireless base station communicates with the wireless terminal using radio waves of different channels. Communicating, at least one of the wireless terminals can receive radio waves of two different wireless base stations, each of the wireless terminals belongs to one of a plurality of classes that receive different content services, and the transmission server The wireless base station is configured to communicate only with wireless terminals belonging to the same class based on the class and location information stored in The features.

  With this configuration, it is possible to maintain stable communication quality even when terminal devices are divided into a plurality of classes and different video and audio services are provided for each class. In other words, when it is necessary to send data limited to a specific class, such as broadcasting to a wireless terminal belonging to a specific class, the delay and delay are lower than when wireless terminals belonging to other classes are mixed. Communication with less fluctuation can be realized. As a result, for example, when broadcasting audio is output from headphones connected to a wireless terminal provided in the seat simultaneously with a speaker provided in the cabin ceiling of the aircraft, it is possible to eliminate a sense of incongruity caused by a shift in output audio. .

  In the wireless communication system of the present invention, the classes have different priorities, and the number of connected wireless terminals per wireless base station to which wireless terminals belonging to the higher class are connected is determined as the wireless terminals belonging to the lower class. You may make it reduce compared with the radio base station to which is connected.

  This improves communication quality by reducing the total amount of data handled by one radio base station connected from a radio terminal belonging to a higher class compared to radio base stations connected from a radio terminal belonging to a lower class. be able to.

  In the wireless communication system of the present invention, the bit rate of content provided to a higher class wireless terminal may be set higher than content provided to a lower class wireless terminal.

  As a result, a higher data rate can be allocated per wireless terminal, so that a higher bit rate video service and a faster file download service can be provided to wireless terminals belonging to a higher class. it can.

  According to the wireless communication system of the present invention, it is possible to provide a wireless communication system capable of maintaining stable communication quality even when terminal devices are divided into a plurality of classes and different video and audio services are provided to the respective classes.

(Embodiment)
The embodiment of the present invention is a wireless communication system that provides services such as video and audio to a user in an aircraft cabin. FIG. 1 is a schematic view of a wireless communication system in an aircraft cabin according to the present embodiment as viewed from the side.

  First, components of the head end unit that sends audio data, video data, control data, and the like to the passenger terminal and receives and processes uplink data sent from the passenger terminal will be described.

  The head end unit has a connection function between the transmission server 101 and a wired transmission path, and has access points 102 to 105 which are wireless base stations that relay between the transmission server and each wireless terminal. The transmission server 101 has a function of storing content / data used in video / audio services provided to passengers, and a function of reading out content / data stored in the transmission server and sending it to a passenger seat terminal. The transmission server 101 further converts in-flight broadcast sound by the captain or flight attendant, video from a camera installed outside the aircraft, video / sound received from satellite broadcast, etc. into digital data and sends it to the passenger seat terminal in real time Etc. can also be provided.

  Data sent from the transmission server 101 is sent to each access point 102 to 105 via a wired transmission path. The access points 102 to 105 can be installed, for example, on the ceiling of the guest room, and can distribute data to wireless terminals via wireless transmission paths. Communication between the transmission server 101 and the access points 102 to 105 may be in accordance with a so-called Internet Protocol (IP) protocol that is a packet communication network. However, the communication protocol is not limited to the Internet protocol, and other communication protocols other than the Internet protocol may be followed. When the Internet protocol is used, the transmission server 101 and the access points 102 to 105 are connected by Ethernet (registered trademark) or the like, and a predetermined data transfer is performed using a packet conforming to the Internet protocol (IP) as a data frame. Exchange between the two according to the procedure. The access points 102 to 105 may exchange data with a receiving facility provided in a seat using a data frame configuration conforming to, for example, IEEE802.11b and its communication procedure as a data link layer.

  Next, components of the passenger seat terminal unit will be described. The passenger seat terminal unit includes wireless client terminals 111 to 119 which are wireless terminals installed in each seat. Each wireless client terminal includes a liquid crystal monitor. Each liquid crystal monitor is installed in the arm rest portion of each seat and the rear portion of the front seat, and provides video / audio to passengers seated in the seat.

  The wireless client terminals 111 to 119 receive radio waves emitted from any of the access points 102 to 105, extract packets obtained from the received data, and reconstruct original various data (video data, audio data, control data, etc.). . The video signal is output and displayed on the LCD monitor.

  Each seat is assigned to a predetermined class. In FIG. 1, the front row seat 1a is assigned to class A, the second and third row seats 2a and 3a are assigned to class B, and the fourth to ninth row seats 4a to 9a are assigned to class C.

  Here, a procedure for installing an access point in an aircraft will be described.

  When installing an access point in an aircraft, first, the position of the access point to be installed is determined. Next, a channel used by each access point is set so that radio wave interference does not occur. Then, in the wireless LAN, an identifier ESSID (Extended Service Set ID) used for logically distinguishing the networks is set in each access point. This completes the preparation on the access point side to use the wireless LAN.

  In addition, in order to establish a connection with a specific access point from a wireless client terminal, an association request packet is transmitted by specifying an ESSID, and a connection is established with an access point with a specified ESSID. Is established and the channel is automatically set.

  FIG. 2 is a diagram illustrating an example of access point setting information in the cabin of the wireless communication system in the aircraft cabin according to the present embodiment, which is registered and stored in the transmission server 101.

  Next, the seat arrangement in the cabin will be described.

  FIG. 3 is a schematic view of a wireless communication system in an aircraft cabin having the same seat arrangement as FIG. 1 as viewed from above.

  The two seats in the front row (seat 1a and seat 1b) are class A, the subsequent four rows (seats 2a, 2b, 3a, 3b) are class B, and the rear seats are class C. Of course, the number of seats is not limited to 30. In the case where the aircraft has 30 or more seats, the system can include 31st and subsequent passenger seat terminals.

  FIG. 4 is a diagram illustrating an example of seat arrangement and class assignment of each seat in the guest room of the wireless communication system described above, and is registered and stored in the transmission server 101.

  The control operation of the wireless connection between each repeater and each terminal device in the present embodiment will be described below with reference to FIGS.

  A connection correspondence table of access points-wireless client terminals is created in advance in the in-flight transmission server. As the method, for example, assignment of access points is determined in order from the wireless client terminal provided in the head seat. If the seat class to which the next assigned wireless client terminal belongs is different from the previous wireless client terminal, or the number of wireless client terminals connected to the access point exceeds the maximum number of connected clients assigned to that class. If so, assign it to a new access point.

  FIG. 5 is a flowchart showing processing for associating an access point and a wireless client terminal in the wireless communication system in the aircraft cabin according to the present embodiment.

  Now, a case will be described where the maximum number of clients connected to the access point is determined as shown in FIG.

  First, the wireless client terminal 111 provided in the seat 1a with seat number 1 in FIG. 4 is assigned to AP1 (steps 301 and 302 in FIG. 5).

  Next, consider the wireless client terminal provided in the seat 1b with seat number 2 (corresponding to j = 2 and i = 1 in steps 304 to 308 in FIG. 5).

  Since both the seat 1a and the seat 1b are equal in class A, it is determined Yes in step 305 (k [2] = A, k [1] = A), and in step 306, the number of AP1 connections is 1 and class A. Since the maximum allowable number of connections is smaller than 6, the determination is Yes.

  Accordingly, the wireless client terminal provided in the seat 1b is also assigned to the AP1.

  Next, since the seat class to which the seat 2a with seat number 3 belongs is B and different from the seat 1b, it is determined No in step 305 (k [3] = B, k [2] = A) and assigned to the next AP2. (If j = 3, i = 2 in step 307).

  Hereinafter, the seats 2b, 3a, 3b are similarly assigned to the AP2.

  Since seat class C is assigned from seat 4a, it is assigned to AP3. Furthermore, seats 4b to 6d are assigned to AP3. At this time, the number of wireless client terminals associated with AP3 is 12, which is the maximum number of connected clients per AP in seat class C shown in FIG.

  For this reason, the seats 7a and later are newly assigned to AP4.

  The above procedure is repeated, and the access point to be connected is determined in order from the top wireless client terminal.

  As a result, as shown in the “access point-wireless client terminal connection correspondence table” in FIG. 7, connection destination access points corresponding to all the wireless client terminals are determined.

  A procedure for connecting each wireless client terminal to the designated connection destination access point based on the connection correspondence table created as described above will be described below.

  FIG. 8 is a flowchart showing a procedure for connecting each wireless client terminal to the designated access point in the wireless communication system in the aircraft cabin according to the present embodiment.

  First, the wireless client terminal that is turned on is connected to a nearby access point (steps 401 and 402).

  A wireless client terminal can connect to a nearby access point by a method called passive scan in which a beacon packet periodically output from the access point is monitored and an ESSID included in the packet is detected. . However, the present invention is not limited to this method. A packet called a probe request is transmitted from a wireless client terminal, and an ESSID is detected by a response from an access point. Any method may be used as long as an equivalent function can be realized, such as a method of trying connections in order using a plurality of ESSIDs.

  After the connection to the nearby access point is completed, the wireless client terminal requests the “access point-wireless client terminal connection correspondence table” from the transmission server (step 403).

  The transmission server requested for the “access point-wireless client terminal connection correspondence table” returns an “access point-wireless client terminal connection correspondence table” to the wireless client terminal (steps 407 and 408).

  The wireless client terminal that has received the “access point-wireless client terminal connection correspondence table” searches the information of the access point designated as the connection destination from its own seat number (steps 404 and 405). Then, it reconnects to the access point designated as the connection destination based on the search result.

  All wireless client terminals in the aircraft perform the same operation, so that all wireless client terminals can connect to the designated access point.

  With the above operation, it is possible to prevent wireless client terminals from being mixed in a plurality of seats at any one access point, and limited to a specific class such as broadcasting to wireless client terminals belonging to a specific class. When it is necessary to send data, communication with lower delay and less delay fluctuation can be realized as compared with the case where wireless terminals belonging to other classes coexist.

  In addition, by assigning a smaller number of wireless terminals connected to wireless base stations connected from wireless terminals belonging to the higher class compared to wireless base stations connected from wireless client terminals belonging to the lower class, one wireless More data rates can be used per terminal, and higher bit rate video services and faster file download services can be provided to wireless terminals belonging to a higher class.

  Further, in this embodiment, when the transmission server sends the “access point-wireless client terminal connection correspondence table” to each wireless client terminal, it is assumed to transmit in a unicast manner as a response to the inquiry from each wireless client terminal. However, it may be transmitted to all wireless terminals by a broadcast communication method or a multicast communication method when the system is activated.

  In the present embodiment, an example in which a passenger aircraft is taken as an example and the wireless communication system according to the present invention is used as an in-flight information system is shown. However, the present wireless communication system is not limited to an aircraft. For example, a wireless client terminal can be provided on a seat arranged in a railway, a ship, an automobile, or the like. Further, the wireless terminal is not limited to the form provided in the seat.

  The wireless communication system according to the present invention saves the trouble of registering the specific information of each wireless terminal in the transmission server, and the communication data for a specific class is affected by the communication data for other classes, so that the communication quality is deteriorated. Can be prevented and communication reliability can be improved. Therefore, the present invention is useful for video / audio data wireless communication services for wireless terminals having a plurality of different classes.

The schematic diagram which looked at the radio | wireless communications system in the aircraft cabin in embodiment of this invention from the side The figure which shows an example of the setting information of the access point in the guest room of the radio | wireless communications system Schematic view of the same wireless communication system viewed from above The figure which shows an example of the seat arrangement in the guest room of the same radio | wireless communications system, and the class assignment of each seat A flowchart showing a process for associating an access point and a wireless client terminal in the wireless communication system The figure which shows the example of the maximum number of connection clients per AP in each seat class of the same radio | wireless communications system The figure which shows the connection correspondence table of the access point and wireless client terminal in the same wireless communication system A flowchart showing a procedure for connecting each wireless client terminal to a designated access point in the same wireless communication system The figure which shows the structure of the conventional radio | wireless communications system

Explanation of symbols

101 transmission server 102-105 access point (radio base station)
111-119 Wireless client terminal 501 Host computer 502, 503 Repeater 504-508 Terminal equipment

Claims (3)

A transmission server, a plurality of wireless base stations connected to the transmission server by wire or wirelessly, and a plurality of wireless terminals arranged to be able to transmit to and receive from the wireless base station, the transmission server passing through the wireless base station A wireless communication system for providing content services including video or audio to the wireless terminal,
The radio base stations communicate with the radio terminals using radio waves of different channels, at least one of the radio terminals can receive radio waves of two different radio base stations, and the radio terminals are different from each other. It belongs to any one of a plurality of classes that receive content services, and the wireless base station communicates only with wireless terminals that belong to the same class based on the class and the information related to the arrangement stored in the transmission server A wireless communication system configured as described above. The classes have different priorities, and the number of connected radio terminals per radio base station to which the radio terminals belonging to the higher class are connected is the radio to which the radio terminals belonging to the lower class are connected. The radio communication system according to claim 1, wherein the radio communication system is reduced as compared with a base station. 3. The wireless communication system according to claim 2, wherein a bit rate of content provided to the upper class wireless terminal is set higher than content provided to the lower class wireless terminal.

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