JP2006033676A - Radio communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a data distribution service high in image quality and high in sound quality without any delay in a PA (Passenger Announce) being emergency attention and explanation items in the case of emergency broadcast inside an airplane. <P>SOLUTION: The radio communication system is composed of: a server for storing and distributing video and audio data or information data; at least one or more radio base stations each connected to the server and including a function capable of switching a unicast radio communication scheme and a multicast radio communication scheme for distributing the data; and a plurality of radio terminals for providing a data service by receiving the data distributed from the radio base stations. The radio communication system can provide a high-speed information data distribution service of high image quality, high sound quality and no delay required for an emergency broadcast or the like without damaging quality of ordinary data distribution services. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a broadband wireless distribution system for a mobile platform in a passenger cabin area such as an aircraft, and a plurality of wireless communication terminal devices arranged in a passenger seat and a server for distributing video, audio, and information services The present invention relates to a wireless communication system for performing wireless communication between connected wireless base stations (wireless access point, Wireless Access Point).

  In recent years, wireless communication systems such as IEEE802.11a / b / g are becoming widespread. These are called wireless local area network (LAN) systems, and can be said to be equivalent to the Ethernet (registered trademark) used in the wired LAN system replaced with wireless.

  The wireless LAN system was initially assumed to be used in a portable or portable personal computer, a portable wireless terminal device, etc., but nowadays, a terminal whose use position is fixed for the purpose of eliminating the complexity of wiring. It is considered to use a wireless LAN system for providing network services to devices.

  FIG. 2 shows an example (hereinafter referred to as a conventional example) of providing a wireless LAN service for a terminal device whose use position is fixed.

  In this conventional example, a wireless LAN system is used to distribute video, audio data, and information data to the wireless terminal device 7 installed in each passenger seat 6 in an aircraft. Video, audio data, and information data are stored in a server (not shown) of the system, and each wireless terminal device 7 installed in each seat has a plurality of wireless base stations connected to the server. Are distributed to each wireless terminal device 7 via a wireless access point (hereinafter referred to as “access point”) 1.

  FIG. 3 is a perspective plan view of the aircraft fuselage, and the reference numerals correspond to those in FIG.

  For a plurality of access points 1 (representatively, only two locations are indicated), the in-flight space is divided into a plurality of areas, and one access point for one area, for example, reference numeral 1 in FIG. Assign only as instructed). A portion indicated by an ellipse 11 (representatively, only two points are indicated) indicates a substantially reachable range of the radio wave emitted from the access point. The access point directional antenna emits a radio wave so as not to interfere and disturb other areas as much as possible, and performs wireless communication with each wireless terminal device 7 in the area using a predetermined channel.

  In this conventional example, a method is adopted in which a frequency band (channel) determined for one access point is time-divided and data is transmitted to a plurality of specific wireless terminal devices 7. In this way, it is possible to provide individual data distribution services such as VOD (Video On Demand, a service in which a desired video can be viewed) for a plurality of wireless terminal devices on one channel. .

In this application, a method for transmitting data to video, audio data and information data to a specific partner is called unicast, and a communication method for distributing to a plurality of unspecified users is called multicast. A communication method for distributing video, audio data, and information data to a plurality of specific partners in a time division manner is described as being unicast in the above sense. (Generally, unicast is used to transmit data to a specific partner, or to compare with a broadcast that transmits data to an unspecified number of other parties. (From the IT Glossary, e-Words.)
By making the communication area into cells in this way, the number of wireless terminal devices to be handled by each access point becomes clear. In addition, each access point can be provided with a directional antenna to cover a narrow area, and communication errors due to radio wave interference can be reduced. Communication quality of data distribution provided to each wireless terminal device can be reduced. Improved and easier to manage
US Patent Application Publication No. 2004/0098745

  However, in the unicast communication method using time division as in the above conventional example, one access point time-divides one channel and distributes data to a plurality of wireless terminal devices, so the bandwidth per wireless terminal device is Narrow. For example, even if the communication speed is 20 Mbps per channel, if there are 20 wireless terminal devices in the area covered by one access point, the wireless terminal device will be 1 Mbps, and if video and audio data are distributed, the image quality will be The sound quality is degraded, or the video and audio are delayed. Moreover, if it is information data, data acquisition time will reduce extremely.

  In particular, at the time of emergency broadcasting in an airplane, PA (Passenger Announce), which is a precautionary matter and explanation, there is a need for a data distribution service that has high image quality, high sound quality, and no delay.

  The present invention solves the above-described conventional problems, and by switching from a unicast communication method that is normally used to a multicast communication method, an individually corresponding data distribution service cannot be performed. The purpose is to provide a high-speed information data delivery service that has high image quality, high sound quality, and no delay required in the case of time and emergency precautions and explanations such as PA.

The wireless communication system according to claim 1 of the present invention is
A server for storing and distributing video, audio data and information data;
At least one or more radio base stations that are connected to the server and have a function of switching between a radio communication system using a unicast method and a radio communication system using a multicast, and distributing the data;
And a plurality of wireless terminal devices that receive the data distributed from the wireless base station and provide a data service.

According to a fourth aspect of the present invention, there is provided a wireless communication system.
A wireless communication system that distributes video, audio data and information data by wireless communication for passengers in a passenger aircraft,
A server for storing and distributing video, audio data and information data;
At least one or more radio base stations that are connected to the server and have a function of switching between a radio communication system using a unicast method and a radio communication system using a multicast, and distributing the data;
A plurality of wireless terminal devices that receive the data distributed from the wireless base station and provide a data service;
It is made up of, and is switched to the wireless communication system by multicast at the time of emergency broadcast in the aircraft, emergency warning, PA (Passenger Announce), which is the explanation item, otherwise it is the wireless communication system by unicast system .

  As described above, the present invention provides high image quality and high image quality necessary for emergency broadcasts, emergency cautions and explanations such as PAs, without compromising the quality of normal data distribution services. It is possible to provide a high-speed information data distribution service with sound quality and no delay.

(Embodiment)
Hereinafter, an embodiment of the present invention will be described with reference to FIG.

  FIG. 1 is a block diagram showing the flow of signals from a server to an access point. 1 is a plurality of access points arranged in the aircraft, 2 is a unicast server, and a channel is divided into a plurality of specific points. A signal for transmitting data to the wireless terminal device is generated, and the access point 1 distributes the signal as a radio wave to each wireless terminal device by the unicast communication method. Each wireless terminal device identifies a signal to be received by the ID in the signal, demodulates it into video, audio or information data and reproduces it.

  Reference numeral 3 denotes a multicast server, which generates a signal for distributing video and audio data such as PA, which is an emergency broadcast or emergency notice, and explanation items, and is transmitted from the access point 1 to each wireless terminal device as a radio wave. Delivered with. Each wireless terminal device identifies a unicast signal and a multicast signal based on a flag in the signal, and when it is determined to be a multicast signal, the signal distributed regardless of the ID is demodulated and reproduced as video and audio data.

  A switch 4 switches between a unicast signal that is normally used and a multicast signal that is used during emergency broadcasting.

  In this embodiment, the unicast server 2, the multicast server 3, and the switch 4 are described separately. However, the present invention is not limited to this, and the unicast server 2, the multicast server 3, and the switch 4 are configured as a single server 5 using a computer and software. The server 5 may be instructed as necessary to distribute the unicast signal and the multicast signal to each access point 1.

  Note that, when emergency broadcasting or PA is distributed, priority is given to normal data distribution. Therefore, when emergency broadcasting or PA distribution is detected, the switch 4 switches over the multicast server, and the wireless terminal device uses a flag or the like. When a multicast signal is received and detected by, a signal distributed with priority over a unicast signal is demodulated into video and audio data and reproduced.

  As described above, the present invention provides high image quality and high image quality necessary for emergency broadcasts, emergency cautions and explanations such as PAs, without compromising the quality of normal data distribution services. It is possible to provide a high-speed information data distribution service with sound quality and no delay.

  The wireless communication system according to the present invention has high image quality necessary for emergency broadcasts, emergency cautions, and explanations such as PA, without compromising the quality of normal data distribution services in an aircraft. It has the effect of being able to provide high-quality sound-free and high-speed information data distribution services, and is installed in passenger seats such as wireless distribution systems for mobile platforms in passenger cabin areas such as aircraft. It is useful as a wireless communication system for wireless communication between a plurality of wireless communication terminal devices and wireless base stations connected to a server that distributes video, audio, and information services.

The block diagram which showed the flow of the signal of the access point from the server in embodiment of this invention The figure which shows an example of the provision form of the wireless LAN service with respect to the terminal device fixed to the conventional passenger seat Perspective plan view of aircraft fuselage of wireless communication system according to conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Access point 2 Unicast server 3 Multicast server 4 Switch 5 Server 6 Passenger seat 7 Wireless terminal device

Claims (4)

A server for storing and distributing video, audio data and information data;
At least one or more radio base stations that are connected to the server and have a function of switching between a radio communication system using a unicast method and a radio communication system using a multicast, and distributing the data;
A plurality of wireless terminal devices that receive the data distributed from the wireless base station and provide a data service;
A wireless communication system composed of: 2. The wireless communication system according to claim 1, wherein when high-quality, high-sound quality, or high-speed information data distribution is required, the wireless communication system is switched to the multicast wireless communication system, and otherwise the unicast wireless communication system is used. The wireless communication system according to claim 1, wherein the server and the wireless base station preferentially distribute data distributed to the wireless terminal device by a multicast communication method over data distributed by a unicast communication method. A wireless communication system that distributes video, audio data and information data by wireless communication for passengers in a passenger aircraft,
A server for storing and distributing video, audio data and information data;
At least one or more radio base stations that are connected to the server and have a function of switching between a radio communication system using a unicast method and a radio communication system using a multicast, and distributing the data;
A plurality of wireless terminal devices that receive the data distributed from the wireless base station and provide a data service;
Consisting of
A wireless communication system that switches to a wireless communication system by multicast at the time of emergency broadcasting in an aircraft, cautions at the time of emergency, and PA (Passenger Announce), which is an explanation matter, and a wireless communication system by a unicast system otherwise.

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