JP2004038242A - Download service system in train - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-train download service system providing an efficient access to Internet at a low cost when a user on a train accesses to Internet. <P>SOLUTION: This on-train download service system is provided with station yard wireless communication means 55 installed in a plurality of stations and wirelessly communicating between terminals in the trains or servers in the trains, a means 51 connected to the station yard wireless communication means 55, accessing to an applicable contents server 40 as a proxy according to the download requirement from the terminal or the server in the train, and acquiring and storing the required contents, a data acquisition station specification means 30 specifying the station acquiring the data required by the terminal or the server in the train, and a contents transfer means 51 transferring the contents acquired by the proxy download to the terminal or the server in the train via the station yard wireless communication means 55 pertaining to the station specified by the data acquisition station specification means 30. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an on-train download service system that can be used when a user on a train accesses a network such as the Internet.
[0002]
[Prior art]
When accessing a network such as the Internet in a mobile environment such as a train, connection to the network is often realized using a wireless communication device such as a mobile phone.
When a mobile phone is used, connection to a network can be realized regardless of whether the user is on a train. In addition, since each wireless area of the mobile phone is relatively large, even when moving at high speed, communication can be continuously performed without switching over wireless areas without switching over wireless areas.
[0003]
There is also an attempt to access the network and download necessary information economically and efficiently by specializing in use on a train. For example, in the technology disclosed in (Nikkei Byte, January 2002, “Hot Spots Spreading on Street Corners”), a user inside a vehicle cannot directly access a network, but a user cannot access a network via a wireless LAN inside the vehicle. The user can access a server in the vehicle and download contents such as a weather forecast, a train timetable, and transit guidance from the server in the vehicle. The in-vehicle server performs wireless communication with a content server installed in a store outside the vehicle at a station on the way via a wireless LAN, downloads content from the content server to the in-vehicle server, and updates the contents of the in-vehicle server.
[0004]
In addition, a satellite radio line can be used for communication between an in-vehicle server in a train and a content server outside the vehicle. In the case of using a satellite radio line, communication is always possible even while the train is moving, so that the contents of the contents in the onboard server can be updated as needed. Therefore, by relaying the user's network access by the in-vehicle server, the user can always access the network and download necessary information.
[0005]
[Problems to be solved by the invention]
However, when a network is accessed using a wireless communication service having a large wireless area, such as a mobile phone, the efficiency of repeated use of radio frequencies is low, so that inefficiency is likely to occur and charges are likely to increase. Therefore, there is a problem in the economics of service.
[0006]
Further, when an in-vehicle server that communicates with a content server via a wireless LAN is used, a user communicates only with the in-vehicle server, and only limited content exists on the in-vehicle server. In addition, various information required by the user cannot be downloaded.
In addition, the in-vehicle server can communicate with the content server in the station premises using the wireless LAN only for a short time while the train is stopped at the station, so that the amount of information that can be exchanged by the in-vehicle server is limited.
[0007]
In a general wireless LAN, a frequency band of 2.4 GHz or 5 GHz is used, and one wireless area has a radius of about 100 m. A band corresponding to a communication speed of 1 to several tens Mbps is shared by a plurality of users in the area.
In addition, when a satellite radio line is used, a communication fee becomes high. Furthermore, since the capacity of the satellite radio line is limited, a problem of communication capacity occurs when it is assumed that many trains nationwide use the same satellite radio line at the same time.
[0008]
An object of the present invention is to provide an on-train download service system capable of providing efficient access at low cost when a user on the train accesses the Internet or the like.
[0009]
[Means for Solving the Problems]
2. The on-train download service system according to claim 1, wherein the on-train download service system is used to download content requested from an arbitrary terminal on the train from a content server connected to a predetermined network and provide the content to the terminal. In the system, station station wireless communication means installed at each of a plurality of stations and capable of wireless communication with the terminal or the in-vehicle server in the train while the train is present in the station premises, A proxy download unit that is connected to a communication unit and accesses a corresponding content server as a proxy of a request source according to a download request from the terminal or the in-vehicle server, and acquires and accumulates the requested content; Data specifying the station from which the data requested by the server is obtained Acquisition station specifying means, and content transfer means for transferring the content obtained by the proxy download means to the terminal or the in-vehicle server via the station premises wireless communication means belonging to the station specified by the data acquisition station specifying means. Is provided.
[0010]
In claim 1, a download request from a terminal (a personal computer or the like) in a train is transferred to a proxy download unit outside the vehicle directly or via an in-vehicle server. According to the received request, the proxy download unit accesses the corresponding content server as a proxy of the request source, and acquires the requested content.
[0011]
The content acquired by the proxy download unit is transferred to the terminal or the in-vehicle server via the station premises wireless communication unit under the control of the content transfer unit when the train stops at any station.
The data acquisition station identification means identifies the train on which the terminal or the like that has output the download request is present, and identifies the station to be used when transferring the requested content to the requesting terminal or the like.
[0012]
Therefore, each terminal in the train can access the Internet or the like using the proxy download means, and acquire information of necessary content in any station premises.
In a train download service system used to download content requested from an arbitrary terminal existing on a train from a content server connected to a predetermined network and provide the content to the terminal, a plurality of stations are provided. Installed in each of the stations, the station premises wireless communication means capable of wireless communication with the terminal or the in-vehicle server in the train while the train is present in the premises of each station, and connected to the station premises wireless communication means, According to a download request from the terminal or the in-vehicle server, the corresponding content server is accessed as a proxy of the request source, and a proxy download unit for acquiring and storing the requested content can be communicated with the station premises wireless communication unit. From the terminal or the in-vehicle server via a wide area wireless communication means Request transfer means for receiving a download request and transferring the received download request to the proxy download means; data acquisition station identification means for specifying a station from which the terminal or the in-vehicle server obtains the requested data; Content transfer means for transferring the content obtained by the means to the terminal or the in-vehicle server via the station premises wireless communication means belonging to the station identified by the data acquisition station identification means.
[0013]
According to the second aspect, similarly to the first aspect, each terminal in the train can access the Internet or the like by using the proxy download means, and can acquire information of necessary contents in any station premises.
[0014]
According to the second aspect, the download request from the terminal in the train or the in-vehicle server is input to the request transfer unit via a wireless line of a wide area wireless communication unit (for example, a mobile phone network or a satellite communication network), and further, the proxy download is performed. Forwarded to the means.
Therefore, the download request can be transmitted even while the train is running, and the request source terminal can efficiently receive the content acquired by the proxy download unit while the train is running at the next stop station. it can.
[0015]
Claim 3 is a train download service system used for downloading content requested from an arbitrary terminal existing in a train from a content server connected to a predetermined network and providing the content to the terminal. In the station premises wireless communication means that can be wirelessly communicated with the terminal or the in-vehicle server in the train while the train is present in the premises of each station, Receiving a download request from the terminal or the in-vehicle server via the wide area wireless communication means having a wide possible range, and accessing the corresponding content server as a proxy of the request source according to the received download request to obtain the requested content Request by the terminal or the in-vehicle server, and the proxy download means for storing and storing Data acquisition station specifying means for specifying a station to obtain the data, and the content obtained by the proxy download means, the terminal or via the station premises wireless communication means belonging to the station specified by the data acquisition station specifying means or And a content transfer means for transferring the content to the in-vehicle server.
[0016]
According to the third aspect, similarly to the first aspect, each terminal in the train can access the Internet or the like by using the proxy download means, and can acquire information of necessary contents in any station premises.
According to the third aspect, the download request from the terminal in the train or the in-vehicle server is input to the proxy download unit via a wireless line of a wide area wireless communication unit (for example, a mobile phone network or a satellite communication network). The content acquired by the proxy download unit is transferred to the terminal or the in-vehicle server via the station premises wireless communication unit belonging to the station identified by the data acquisition station identification unit.
[0017]
Therefore, the download request can be transmitted even while the train is running, and the request source terminal can efficiently receive the content acquired by the proxy download unit while the train is running at the next stop station. it can.
According to a fourth aspect, in the train download service system according to any one of the first, second, and third aspects, a train information holding unit that holds a train number specifying each train and operation schedule information of each train. Further provided, the data acquisition station specifying means, based on the train number included in the received information and the content of the information held by the train information holding means, to specify the next stop station of the corresponding train Features.
[0018]
In claim 4, since the train information holding means holds the train number and the operation schedule information of each train, if the train number and the current time are known, the station where the corresponding train stops next is specified from the operation schedule. can do.
According to a fifth aspect of the present invention, in the train download service system according to any one of the first, second, and third aspects, the content storage means for storing the content obtained by the proxy download means is arranged at each of the plurality of stations. In addition, station information holding means for holding the correspondence between each content storage means and each station is further provided.
[0019]
According to the fifth aspect, the content storage unit associated with a specific station can be specified based on the information held by the station information storage unit. Therefore, it is possible to specify the content storage means of the transfer destination of the content acquired by the proxy download means.
According to a sixth aspect of the present invention, in the train download service system according to any one of the first, second, and third aspects, the in-vehicle server sends information of a corresponding train number together with the download request. I do.
[0020]
According to the sixth aspect, the in-vehicle server in the train transmits the information of the train number, so that the station used for the content data transfer with the train is specified based on the train number and the operation schedule information of the train. Can be.
According to a seventh aspect of the present invention, in the train download service system according to the second or third aspect, the wide area wireless communication means performs communication using a wireless line of a mobile phone network.
[0021]
According to the seventh aspect, since communication is performed using a wireless line of a mobile telephone network, communication can be performed at all times even while a train is running, and a download request from a user terminal or an in-vehicle server is immediately transmitted. be able to.
According to an eighth aspect of the invention, in the train download service system according to the seventh aspect, at least one of the proxy download unit, the request transfer unit, and the data acquisition station specifying unit includes a mobile telephone network communication unit for connecting to a mobile telephone network. It is characterized by having been provided.
[0022]
In claim 8, the proxy download means, the request transfer means or the data acquisition station specifying means can be connected to the mobile telephone network and receive a download request from a user terminal or an in-vehicle server.
According to a ninth aspect of the present invention, in the train download service system according to any one of the first, second and third aspects, the data acquisition station specifying means transmits address information of at least one of an in-vehicle server and a terminal in each train. It is characterized by holding.
[0023]
According to the ninth aspect, the in-vehicle server or terminal of each train to which the content acquired by the proxy download unit is transferred can be specified by the address information held by the data acquisition station identification unit.
According to a tenth aspect, in the train download service system according to any one of the first, second, and third aspects, at least one of an in-vehicle server and a terminal in each train forms part of a local IP network. It is characterized by.
[0024]
According to the tenth aspect, each terminal in the train can receive the service only by connecting to the local IP network in the train using the network communication function.
According to an eleventh aspect, in the train download service system according to any one of the first, second, and third aspects, the content transfer means is used when at least one of an in-vehicle server and a terminal in the train performs wireless communication. It is characterized by holding information of a MAC (Media Access Control) address or an IP address.
[0025]
According to the eleventh aspect, the content transfer unit can specify the transfer destination terminal or the in-vehicle server using the information of the held MAC address or IP address.
According to a twelfth aspect of the present invention, in the train download service system according to any one of the first, second and third aspects, the content transfer means includes a correspondence relationship between a train number and an entry number of each station, or a vehicle number and a stop. It is characterized by holding information indicating a correspondence relationship with a position.
[0026]
According to claim 12, when a device having a very narrow communication range such as a wireless LAN device is used as a wireless communication device, a correspondence between a train number and an entry line number of each station (track number of a stop platform) or a vehicle A communicable wireless communication device can be specified based on the correspondence between the number and the stop position.
By determining the installation position of the antenna of each wireless communication device in the station premises according to the assumed stop position of the train and the installation position of the antenna on the train in the station premises, the wireless device on the train and the station premises The wireless device on the home is located at a short distance within the line of sight. For this reason, a wireless LAN device using a frequency band in a high frequency region (for example, 10 GHz or more) that can be used only in line-of-sight communication, FWA (Fixed Wireless Access: subscriber wireless access system), IrDA (infrared communication), etc. Communication technology can be applied.
[0027]
According to a thirteenth aspect of the present invention, in the train download service system according to the twelfth aspect, a plurality of the station premises wireless communication means are arranged at mutually different locations in a station yard of each station, and the content transfer means is provided with the plurality of station premises wireless communication means. The content is transferred to the terminal or the in-vehicle server by selectively using one of the means.
[0028]
According to claim 13, one of the plurality of station premises wireless communication means arranged in the station premises is selectively used by using one station premises wireless communication means capable of communicating with a terminal in a train or an in-car server. Content can be transferred to a terminal or an in-vehicle server.
Claim 14 is a wireless communication between a plurality of wireless communication devices installed in the station premises, a content server connected to the wireless communication device via a network, and the wireless communication device installed in a train In a train download service system including a train wireless communication device capable of communicating with a terminal in a train or a server in a train, a proxy download unit that downloads and holds predetermined content from the content server, The communication device selecting means for selecting one of the plurality of wireless communication devices, and the content acquired by the proxy download means is transmitted to the terminal in the train or the in-vehicle via the wireless communication device selected by the communication device selecting means. Content transfer means for transferring the content to a server is provided.
[0029]
In claim 14, the proxy download means downloads the predetermined content from the content server and holds the content. The information on the content obtained by the proxy download unit is controlled by the content transfer unit, and among the plurality of wireless communication devices in the station yard, the terminal or the terminal in the train via the wireless communication device selected by the communication device selection unit. It is transferred to the in-vehicle server.
[0030]
A wireless communication device installed in a station, a content server connected to the wireless communication device via a network, a wireless communication device installed in a train and the wireless communication device, In a train download service system including a wireless communication device in a train capable of communicating with a terminal or an in-vehicle server, a station to be used for download is selected according to a predetermined schedule, and the selected station is selected. Schedule management means for transmitting a download request to a station, proxy download means arranged at each station, for acquiring and accumulating content from the content server in accordance with the download request from the schedule management means, and acquiring by the proxy download means Content on the train via the wireless communication device Characterized in that a content transfer means for transferring the terminal or car server.
[0031]
In claim 15, the schedule management means selects a station to be used at the time of downloading according to a predetermined schedule, and transmits a download request to the selected station. The proxy download means arranged at each station acquires and accumulates the content from the content server in accordance with the download request from the schedule management means. The content transfer means transfers the content acquired by the proxy download means to a terminal in a train or a server in a vehicle via the wireless communication device.
[0032]
BEST MODE FOR CARRYING OUT THE INVENTION
(First Embodiment)
One embodiment of the on-train download service system of the present invention will be described with reference to FIGS. 1 to 8 and FIG. This embodiment is a specific example corresponding to claim 1, claim 2, claim 4 to claim 10 and claim 12 to claim 15.
[0033]
FIG. 1 is a block diagram showing a configuration example of the system. FIG. 2 is a block diagram showing the configuration of the train device. FIG. 3 is a flowchart showing the operation of the scheduler. FIG. 4 is a flowchart showing the operation of the cache server. FIG. 5 is a schematic diagram showing the configuration of the IP address management table on the scheduler.
FIG. 6 is a schematic diagram showing the configuration of the download request IP packet. FIG. 7 is a schematic diagram showing the structure of the encapsulated download request IP packet. FIG. 8 is a schematic diagram showing the configuration (1) of the session management table on the cache server. FIG. 10 is a plan view showing an example of the arrangement of the system.
[0034]
In this embodiment, the terminal content server, the station wireless communication means, the proxy download means, the data acquisition station specifying means, and the content transfer means of claim 1 and claim 2 are respectively a user terminal 19, a content server 40, a wireless LAN base station. 55, the cache server 51, the scheduler 30, and the cache server 51. Further, the wide area wireless communication means and the request transfer means in claim 2 correspond to the mobile telephone network 20 and the scheduler 30, respectively.
[0035]
The train information holding means of claim 4 corresponds to the train management table 31. The station information holding means in claim 5 corresponds to the train management table 31. The portable telephone network communication means of claim 8 corresponds to the interface 33.
The wireless communication device, the content server, and the on-train wireless communication device correspond to the wireless LAN base station 55, the content server 40, and the wireless LAN wireless device 17, respectively. The selection means and the content transfer means correspond to the cache server 51.
[0036]
The wireless communication device, the content server, the on-train wireless communication device, the schedule management means, the proxy download means, and the content transfer means according to claim 15, wherein the wireless LAN base station 55, the content server 40, the wireless LAN wireless device 17, the scheduler 30 , The cache server 51 and the cache server 51.
In this embodiment, it is assumed that a network access for acquiring data of a content existing in a content server 40 arranged on the Internet 25 is performed from a user terminal (for example, a personal computer) 19 existing in the train 11. .
[0037]
As shown in FIG. 1, in this example, a scheduler 30, a content server 40, and a cache server 51 are connected to the Internet 25. The cache server 51 is installed in the station premises 50 of each station where the train 11 stops.
A plurality of wireless LAN base stations (access points) 55 (1), 55 (2),... Are connected to the LAN in the same station premises 50. The scheduler 30 is connected to the mobile phone network 20 via an interface 33.
[0038]
Each vehicle of the train 11 has a vehicle-mounted antenna 13 (1), 13 (2),... For communicating with the wireless LAN base stations 55 (1), 55 (2),.・ ・ Is provided. In addition, the vehicle-mounted antenna 12 is provided on the train 11 for wireless communication with the mobile phone network 20.
In general, at each station, a track (home) through which each train passes and a stop position of each vehicle when the train stops are determined in advance. Therefore, the installation positions of the wireless LAN base stations 55 (1), 55 (2),... Are determined on the assumption that the respective vehicles will be stopped.
[0039]
That is, the positional relationship between each wireless LAN base station 55 (1), 55 (2),... And each on-vehicle antenna 13 (1), 13 (2),. Are positioned so that the distance between the wireless LAN base stations 55 (1), 55 (2),... Is sufficiently short. Each wireless LAN base station 55 has a built-in antenna.
Therefore, when the train 11 is stopped at a regular position at each station, wireless communication can be performed between the wireless LAN base station 55 and the vehicle-mounted antenna 13 in a favorable communication state.
[0040]
In the example of FIG. 10, the in-vehicle antenna 13 (1) mounted on the stopped first vehicle and the wireless LAN base station 55 (1) face each other, and the on-vehicle antenna 13 (1) mounted on the second vehicle is stopped. (2) and the wireless LAN base station 55 (2) face each other, and the in-vehicle antenna 13 (3) mounted on the third vehicle and the wireless LAN base station 55 (3) face each other. The wireless LAN base station 55 is located.
[0041]
As shown in FIG. 2, the train 11 includes an in-vehicle server 15, a mobile phone wireless device 16, a wireless LAN wireless device 17, and a wireless LAN base station 18. The in-vehicle server 15 and the wireless LAN base station 18 are connected by a local IP network, that is, a LAN.
[0042]
The cache server 51 of the station premises 50 has its own global IP address. In addition, a function of dynamically temporarily assigning a global IP address to the in-vehicle server 15 of the stopped train 11 is provided.
The cache server 51 downloads content from the content server 40 or the like via the Internet 25 in accordance with a request from a user in the train 11, and temporarily stores the acquired content information.
[0043]
In addition, the cache server 51 holds information on an entry number (a number of a track or a platform to be passed) for each train at a station where the cache server 51 is installed, and information on a stop position of each vehicle.
As in the case of a general Web server, the content held in the content DB (database) 41 of the content server 40 can be acquired by specifying a URL (Uniform Resource Locator).
[0044]
As shown in FIG. 2, a wireless device for a mobile phone (for example, a mobile phone) 16 and a wireless device for a wireless LAN 17 are connected to an in-vehicle server 15 in the train 11. Therefore, the in-vehicle server 15 can communicate with the scheduler 30 via the mobile phone wireless device 16, the in-vehicle antenna 12, and the mobile phone network 20.
The scheduler 30 manages a content download request transmitted from the user terminal 19 or the in-vehicle server 15. Further, the scheduler 30 automatically determines at which station the information of the requested content should be transferred to the train 11.
[0045]
The scheduler 30 includes a train management table 31 and an IP address management table 32.
The train management table 31 holds predetermined train operation schedule information (route, stop station, departure time). The train management table 31 also stores information indicating the correspondence between the IP address of each cache server 51 and the station where the cache server 51 is installed.
[0046]
In addition, the scheduler 30 determines the local IP addresses of all the in-vehicle servers 15 and the local IP addresses that the in-vehicle server 15 can assign to the in-vehicle user terminals 19 for all trains to be provided with services provided by this system. The IP addresses are managed using the IP address management table 32 so that the ranges do not overlap with each other, and a local IP address is assigned to the user terminal 19 as necessary.
[0047]
For example, as shown in FIG. 5, the IP address management table 32 holds a correspondence relationship between each local IP address, a train number, and a vehicle number (a number for distinguishing a plurality of vehicles constituting each train).
Since the scheduler 30 also operates as a gateway between the local IP network and the global Internet, a local IP address is assigned to one of the plurality of input / output ports of the scheduler 30 that is connected to the in-vehicle server 15 via the mobile phone network 20. A global IP address is assigned to the side connected to the Internet 25.
[0048]
The in-vehicle server 15 can be connected to the mobile phone network 20 via the mobile phone wireless device 16 and the in-vehicle antenna 12. The in-vehicle server 15 can communicate with the outside of the vehicle via the wireless LAN via the wireless LAN wireless device 17 and the on-vehicle antenna 13. Actually, when the train 11 stops at each station, wireless communication is performed between any of the wireless LAN base stations 55 that are within the communicable range of the in-vehicle antenna 13 and the in-vehicle antenna 13.
[0049]
Further, a wireless LAN base station 18 is connected to the in-vehicle server 15 in order to provide a wireless LAN connection service to a user in the train 11. That is, the user terminal 19 equipped with a wireless LAN card or the like can perform wireless communication with the wireless LAN base station 18 and can communicate between the user terminal 19 and the in-vehicle server 15.
[0050]
In this embodiment, the in-vehicle server 15 has a function of a DNS (Domain Name Server) device.
The in-vehicle server 15 assigns a local IP address to each user terminal 19 in the in-vehicle and holds information on the assigned IP address. The in-vehicle server 15 holds the local IP address assigned to itself.
[0051]
The scheduler 30 manages the local IP address of the in-vehicle server 15 itself, the local IP address assigned by the in-vehicle server 15 to the user terminal 19 or a range thereof, and the scheduler 30 notifies the in-vehicle server 15 in advance.
When it is necessary to specify the position of each user terminal 19 in each vehicle of the train 11 in more detail, for example, a wireless tag is installed at each seat position in the vehicle, and an address and a seat number of the wireless tag are output. The information may be registered in the in-vehicle server 15.
[0052]
Procedures and operations for downloading content using the system shown in FIGS. 1 and 2 will be described below in four stages.
[First stage]
Here, an operation until the information such as the destination URL of the content server 40 is notified to the scheduler 30 will be described.
[0053]
The scheduler 30, the in-vehicle server 15 in each vehicle of each train, and the user terminal 19 in each vehicle of each train configure one local IP network (intranet).
The user in the car who wants to acquire the content from the content server 40 inputs the URL corresponding to the target content in the content server 40 to the browser of the user terminal 19.
[0054]
In response to this input, the user terminal 19 generates a query IP packet relating to the IP address. This interrogation IP packet contains the input target URL information, with the local IP address of the user terminal 19 as the source IP address and the local IP address of the in-vehicle server 15 (DNS) as the destination IP address.
[0055]
The query IP packet generated by the user terminal 19 is input to the DNS device of the in-vehicle server 15 via the wireless LAN base station 18. In this case, the DNS device of the in-vehicle server 15 generates an IP packet for answering the question. The answer IP packet includes information on the global IP address of the content server 40. The source IP address and destination IP address in the answer IP packet are obtained by exchanging the source IP address and destination IP address of the query IP packet.
[0056]
The reply IP packet is transmitted from the in-vehicle server 15 to the user terminal 19 via the wireless LAN base station 18. Therefore, the user terminal 19 can acquire the global IP address corresponding to the target URL.
If the global IP address corresponding to the URL is unknown in the DNS device of the in-vehicle server 15, the scheduler 30 sends a query packet out of the local IP network using the scheduler 30 as a gateway, so that it can be used for ordinary Internet access. Address resolution is performed by DNS in a similar manner.
[0057]
Next, the user terminal 19 generates a content download request IP packet having a configuration as shown in FIG. The source IP address of this packet is the local IP address of the own station (19), and the destination IP address is a global IP address corresponding to the URL obtained in the above procedure. Further, information such as a URL is put in the payload portion of the packet.
[0058]
This content download request IP packet is transmitted from the user terminal 19 to the in-vehicle server 15 via the wireless LAN base station 18.
The in-vehicle server 15 analyzes the destination IP address of the received packet. When the content download request IP packet is received, the in-vehicle server 15 communicates with the scheduler 30 using the mobile phone wireless device 16 because the destination IP address is the global IP address.
[0059]
When a connection is established between the in-vehicle server 15 and the scheduler 30 via the mobile phone network 20, the in-vehicle server 15 transmits a content download request IP packet to the scheduler 30.
[Second stage]
Next, the operation of the scheduler 30 when a content download request IP packet is received will be described. An outline of this operation is shown in FIG.
[0060]
Upon receiving the content download request IP packet in step S11 of FIG. 3, the scheduler 30 returns an ACK or the like in step S12 as a response.
In step S13, the source IP address of the received content download request IP packet is referred to, the IP address management table 32 (see FIG. 5) is checked, and the train number and vehicle number corresponding to the source IP address, that is, which train It detects whether a request has been received from both eyes.
[0061]
In step S14, the train operation schedule in the train management table 31 is referred to, and based on the train number and the current time detected in step S13, the station name of the station where the corresponding train 11 stops next is specified.
In step S15, the global IP address of the cache server 51 corresponding to the station name specified in step S14 is obtained based on the information held in the train management table 31. That is, the address of the cache server 51 existing at the next stop which is convenient for receiving the content requested by the requesting user is acquired.
[0062]
In step S16, the scheduler 30 encapsulates the content download request IP packet received from the in-vehicle server 15. That is, as shown in FIG. 7, an IP packet including the received content download request IP packet, the source IP address as the global IP address of the scheduler 30 and the destination address as the global IP address of the corresponding cache server 51 is generated.
[0063]
In step S17, the scheduler 30 transfers the encapsulated content download request IP packet to the target cache server 51 via the Internet 25.
At the same time, the scheduler 30 transmits the local IP address of the requesting user terminal 19 and the information of the train number and the vehicle number to the cache server 51 as IP packets (S18). The local IP address of the user terminal 19 is included in the content download request IP packet received by the scheduler 30 as the source IP address.
[0064]
The operation shown in FIG. 3 can be applied when the train 11 is operating as scheduled. If the train 11 is not operating as scheduled, the operation may be changed, for example, as described below.
(1) At the time of departure from each station, the in-vehicle server 15 notifies the scheduler 30 of “departure from xx station”.
[0065]
(2) In the scheduler 30, the correspondence between the train number and the departure station is stored in the train management table 31 for each train, and the departure station information is received each time the "departure" notification from the onboard server 15 is received. Update and grasp the actual train operation status. This information is used instead of the train operation schedule.
(3) The operation of the scheduler 30 when receiving the content download request IP packet from the in-vehicle server 15 is based on the actual train operation status detected as described above, instead of the “train operation schedule” in step S14. It is the same as FIG. 3 except that it is used.
[0066]
[Third stage]
Next, an operation until the cache server 51 downloads the content will be described. The cache server 51 operates on behalf of the user terminal 19 that is the content request source. The specific operation of the cache server 51 is shown in FIG.
[0067]
In step S21 of FIG. 4, the cache server 51 receives the encapsulated content download request IP packet from the scheduler 30. Also, an IP packet including information such as a train number is received at the same time.
The cache server 51 manages the train number, vehicle number, and communication (session) information required for processing in the session management table 52 in association with each other for each received request.
[0068]
In the session management table 52, information as shown in FIG. 8 is managed for each request. The train number, vehicle number, and local IP address of the user terminal 19 are extracted from the packet received from the scheduler 30 and stored in the session management table 52 (S22). Other areas of the session management table 52 are initially empty.
[0069]
Note that the incoming and outgoing upper and lower logical port numbers are the incoming and outgoing logical port numbers when the direction toward the content server 40 is up and the reverse direction is down, and is composed of a total of four numbers.
In step S23, the cache server 51 extracts the contents of the received packet (encapsulated content download request IP packet) and rewrites the source IP address (local IP address of the user terminal 19) to the IP address of the cache server 51 itself. .
[0070]
Further, the cache server 51 writes the destination IP address (IP address of the content server 40) of the received packet in the session management table 52 in association with the local IP address of the user terminal 19. Further, information on the upstream and downstream logical port numbers is also extracted from the packet before encapsulation and written into the session management table 52.
[0071]
In step S24, a content download request IP packet is transmitted to the Internet 25. In this example, it is assumed that the sending and receiving logical port numbers of the packets to be transmitted are not rewritten, but they may be rewritten as needed.
The content download request IP packet transmitted by the cache server 51 in step S24 is received by the content server 40. The content server 40 analyzes the content of the received bucket and returns a response such as ACK to the cache server 51.
[0072]
At this time, since the downstream logical port number is determined, each communication (session) can be specified by the destination IP address (IP address of the content server 40) and the upper and lower logical port numbers.
When the ACK or the like is received, the cache server 51 writes the information of the downlink logical port number corresponding to the empty downlink logical port number storage area for the session management table 52 having the same destination IP address. .
[0073]
Thereafter, the content server 40 transmits the information of the requested content to the cache server 51.
The cache server 51 receives the information on the content transmitted from the content server 40, stores the information in an appropriate storage area, and writes a pointer indicating the storage area in the corresponding storage area item of the session management table 52.
[0074]
Thereafter, the cache server 51 releases the session with the content server 40.
[Fourth stage]
Next, an operation for transferring the content acquired by the cache server 51 to the requesting user terminal 19 will be described.
[0075]
The cache server 51 holds train operation schedule information at the station where it is installed. The train operation schedule information includes, for each train number, a corresponding entry number of the station (the number of the track or platform to be passed), a stop position when the vehicle of each vehicle number stops, and a corresponding stop position. Information on the number of the attached wireless LAN base station 55 is registered.
[0076]
When the acquisition of the requested content from the content server 40 is completed, the cache server 51 performs, based on the information held in the session management table 52 and the train operation schedule information of this station held by the cache server 51, The stop position corresponding to the requesting user terminal 19 is specified.
That is, the train number and the vehicle number (corresponding to the position of the request source) are obtained from the contents of the session management table 52 corresponding to the requested content, and these are applied to the train operation schedule information to obtain the corresponding train 11 and vehicle number. The home where the vehicle stops and the stop position are specified, and one wireless LAN base station 55 (n) that can communicate with the wireless LAN wireless device 17 in the train 11 at the stop position is selected (S27).
[0077]
In step S28 in FIG. 4, the cache server 51 sends the acquired information and session information to the specific secondary cache device 56 (n) corresponding to the specific wireless LAN base station 55 (n) selected in step S27. The contents of the management table 52 are transmitted.
As for the content of the session management table 52 to be transmitted, the content of the storage area is changed to the content corresponding to the storage area on the secondary cache device 56.
[0078]
In the example of FIG. 10, a plurality of wireless LAN base stations 55 (1), 55 (2), and 55 (55) are arranged on one platform of the station premises 50 along the direction in which the trains 11 are arranged at intervals equal to the length of the vehicles. (3), ... are installed. Also, the wireless LAN base stations 55 (1), 55 (2), 55 (3),... Are respectively connected via secondary cache devices 56 (1), 56 (2), 56 (3),. Connected to the cache server 51.
[0079]
On the other hand, the train 11 entering this platform is a three-car train, and each vehicle of the train 11 is equipped with an on-board antenna 13, a wireless LAN wireless device 17, and an in-vehicle server 15.
In the example of FIG. 10, the user having the user terminal 19 is in the third vehicle. Assuming that this user has transmitted a content download request IP packet from the user terminal 19, the session management table 52 of the cache server 51 indicates the train number specifying the train 11 and the third vehicle on which the requesting user is riding. The information of the vehicle number indicating the vehicle is held.
[0080]
Therefore, in the example of FIG. 10, the cache server 51 transmits the acquired content information and the content of the session management table 52 to the secondary cache device 56 (3) connected to the wireless LAN base station 55 (3).
In this example, each wireless LAN base station 55 is mounted on a pillar or ceiling of a home.
[0081]
On the other hand, each of the on-vehicle antennas 13 on the train 11 is mounted on the roof or the side of the vehicle body of the train 11, and is arranged to face the wireless LAN base station 55 on the home side as shown in FIG.
Usually, the stop position accuracy of the train is about several tens cm. Therefore, the distance between the wireless LAN base station 55 and the in-vehicle antenna 13 facing each other when the vehicle is stopped can be made very small, and there is usually no obstacle between the wireless LAN base station 55 and the in-vehicle antenna 13. .
[0082]
Therefore, various communication means can be used for wireless communication between the train side and the platform side of the station.
That is, it is possible to use not only generally used wireless LAN devices (2.4 GHz and 5 GHz) but also wireless LAN devices having higher frequencies and wireless communication devices such as FWA and IrDA.
[0083]
In this embodiment, a directional antenna is used as the antenna built in the wireless LAN base station 55 and each of the on-vehicle antennas 13. Therefore, even when the plurality of wireless LAN base stations 55 use the same communication frequency, it is possible to prevent the communication of the respective devices from interfering with each other.
When the train 11 enters the home, the wireless LAN base station 55 on the home side and the wireless LAN wireless device 17 on the train 11 each detect that they have entered the wireless LAN communication area, and establish a wireless link.
[0084]
The secondary cache device 56 has a global IP address, and dynamically assigns the global IP address to the in-vehicle server 15 of the stopped train 11 by dynamic control.
After that, the secondary cache device 56 transmits the information of the held content and the content of the session management table 52 to the wireless LAN wireless device 17 in the vehicle through one wireless LAN base station 55 by IP communication.
[0085]
The in-vehicle server 15 receives and accumulates the content and related information transmitted from the secondary cache device 56 via the wireless LAN wireless device 17. At this time, the in-vehicle server 15 updates and holds the information of the pointer indicating the storage area of the content.
Thereafter, the in-vehicle server 15 operates as a proxy for the content server 40 for the user terminal 19.
[0086]
That is, the in-vehicle server 15 obtains the local IP address of the user terminal 19 that has requested the corresponding content, and performs a TCP connection setting for downloading the content to the address. Then, the requested content is read from the storage area and transmitted to the user terminal 19. Thereby, the user terminal 19 can download the target content.
[0087]
In this embodiment, it is assumed that a content download request from the user terminal 19 is transmitted to the scheduler 30 via the mobile phone network 20, but the wireless LAN for each station is used at each station without using the mobile phone network 20. When communication is possible between the device 17 and the wireless LAN base station 55, a content download request from the user terminal 19 is sent to the cache server 51 using a wireless LAN line, and the content download request is further downloaded from the cache server 51 to the scheduler 30. The request may be forwarded.
[0088]
In addition, the scheduler 30 manages the train operation schedule information, and simultaneously registers and manages the URL of the content associated with each vehicle of each train, and the scheduler 30 performs the content instead of the user according to the train operation schedule. If the download request is configured to be transmitted to the cache server 51 of the corresponding station, the cache server 51 can acquire different contents for each train and each vehicle and transfer the content to the user terminal 19.
[0089]
Also, in this embodiment, it is assumed that the content requested by the user is downloaded by the cache server 51, but the cache server 51 may be configured to automatically acquire only predetermined specific content. . In that case, the scheduler 30 and the mobile phone network 20 become unnecessary.
However, by using a communication line such as the mobile phone network 20, a download request for the content desired by the user can be transmitted even while the train is running, so that efficient download is realized.
[0090]
(Second embodiment)
Another embodiment of the in-train download service system of the present invention will be described. This embodiment corresponds to claim 3.
In this embodiment, the station wireless communication means, the proxy download means, the data acquisition station specifying means, and the content transfer means of claim 3 correspond to the wireless LAN base station 55, the scheduler 30, the scheduler 30, and the cache server 51, respectively.
[0091]
This embodiment is a modification of the first embodiment. In this embodiment, a system having the same configuration as that of FIGS. 1 and 2 is assumed.
However, in this embodiment, the device that downloads the content from the content server 40 on behalf of the user is changed to the scheduler 30. Among the operations of the system, the above-mentioned “first stage” and “fourth stage” are the same as those in the first embodiment.
[0092]
The changed parts will be described below. The operations corresponding to the “second stage” and the “third stage” will be described here as (first half procedure) and (second half procedure), respectively.
[First half procedure]
As in the first embodiment, the content download request IP packet is transmitted from the user terminal 19 and transferred to the scheduler 30 via the in-vehicle server 15 and the mobile phone network 20.
[0093]
In this embodiment, the scheduler 30 acquires content and necessary information from the content server 40 on behalf of the user in accordance with the received content download request IP packet. The specific operation is as follows.
The scheduler 30 holds a session management table (corresponding to 52 in FIG. 1) configured as shown in FIG. 8 in order to manage requests from each user terminal 19. In this session management table, correspondences between train numbers, vehicle numbers, and communications (sessions) are held.
[0094]
The scheduler 30 refers to the content download request IP packet from the user terminal 19 that has arrived via the mobile phone network 20, and reads the source IP address. Then, the IP address management table 32 (see FIG. 5) is checked to find out which train (train number) and which eye (vehicle number) the IP address corresponds to. Then, the scheduler 30 writes information in the items of the train number, the vehicle number, and the local IP address of the user terminal 19 in the session management table. Other areas of the session management table are initially empty.
[0095]
The scheduler 30 rewrites the source IP address (local IP address of the user terminal 19) of the content download request IP packet from the user terminal 19 that has arrived via the mobile phone network 20 to the IP address of the scheduler 30 itself, and (The IP address of the content server 40) and the upstream and downstream logical port numbers are written in the session management table in association with the local IP address of the user terminal 19 that made the request.
[0096]
Then, the scheduler 30 transmits the content download request IP packet whose source IP address has been changed to the Internet 25. In some cases, it is necessary to rewrite the upstream and downstream logical port numbers.
The content download request IP packet transmitted by the scheduler 30 is received by the content server 40. The content server 40 analyzes the contents of the received packet and returns a response such as ACK to the scheduler 30.
[0097]
At this time, since the downstream logical port number is determined, the scheduler 30 can specify each communication (session) by the destination IP address (IP address of the content server 40) and the upper and lower logical port numbers.
The scheduler 30 writes the downlink port number in the downlink port area of the session management table (FIG. 8) in which the destination IP address matches and the port number is empty.
[0098]
Thereafter, the content server 40 transmits the requested content and information to the scheduler 30.
The scheduler 30 receives the content transmitted from the content server 40, holds the content in an appropriate storage area, and writes a pointer to the storage area in the storage area column of the session management table. Thereafter, the session with the content server 40 is released.
[0099]
[Second half procedure]
Next, the scheduler 30 specifies the station name of the next stop station of the applicable train based on the current time, the operation schedule information of the train, and the acquired train number. Further, the scheduler 30 acquires the global IP address of the cache server 51 existing at the next stop station by referring to the contents of the table holding the correspondence between the station name and the global IP address of the cache server 51.
[0100]
Next, the scheduler 30 transmits the contents of the session management table to the cache server 51 of the next stop station via the Internet 25 using the acquired global IP address. However, the storage area column of the session management table is left blank.
The cache server 51 acquires and holds the contents of the session management table transmitted from the scheduler 30.
[0101]
Next, the scheduler 30 reads from the storage device the content information acquired in advance from the content server 40 and transfers the information to the cache server 51 via the Internet 25.
The cache server 51 stores the content information transmitted from the scheduler 30 in an internal storage device, and writes the information in the storage area of the session management table holding a pointer indicating the storage area.
[0102]
In this example, the control is performed on the assumption that the train is operating as scheduled. However, even when the actual operation status of the train is different from the operation schedule, the present invention can be implemented by controlling as follows.
[Modification of the latter half procedure]
The in-vehicle server 15 in each train notifies the scheduler 30 of "departure from ** station" when departing from each station.
[0103]
The scheduler 30 holds a table indicating the correspondence between the train number and the departure station for each train, and updates the contents of this table each time a notification “departure from ** station” is received from each train.
[0104]
Then, the scheduler 30 specifies the next stop station name based on the train operation schedule information, the train number, and the information on the departure station. Further, the scheduler 30 acquires the global IP address of the cache server 51 existing at the next stop station with reference to the table indicating the correspondence between the station name and the global IP address of the cache server 51.
[0105]
Next, the scheduler 30 transmits the contents of the session management table to the cache server 51 via the Internet 25 using the acquired global IP address. However, the storage area column of the session management table is sent empty.
The cache server 51 receives and holds the session management table transmitted by the scheduler 30.
[0106]
Next, the scheduler 30 reads the information of the content obtained from the content server 40 from the storage device, and transfers the information to the cache server 51 via the Internet 25.
The cache server 51 stores the information of the content transferred from the scheduler 30 and writes the information in the storage area of the session management table holding the pointer indicating the storage area.
[0107]
(Third embodiment)
Another embodiment of the on-train download service system of the present invention will be described with reference to FIG.
This embodiment is a modification of the first embodiment. The following description of components and operations common to the first embodiment is omitted.
[0108]
In this embodiment, the user terminal 19 owned by each user directly communicates with a device outside the train without disposing the dedicated in-vehicle server 15 in the train. Further, the scheduler 30 is omitted. Of course, the system can be configured using the scheduler 30 as in the first embodiment.
[0109]
As shown in FIG. 11, a wireless LAN communication device (for example, a wireless LAN card) 61 and a mobile phone communication device (for example, a mobile phone) 62 are connected to the user terminal 19 in the train.
Therefore, when the train is stopped at the station, the user terminal 19 in the train can perform wireless LAN communication with the wireless LAN base station 55 in the station via the wireless LAN communication device 61. Further, the user terminal 19 can be connected to the mobile phone network 20 via the mobile phone communication device 62.
[0110]
As in the first embodiment, the station premises 50 of each station includes a cache server 51 and a plurality of wireless LAN base stations 55. These are connected by LAN. A secondary cache device 56 is disposed between the cache server 51 and each wireless LAN base station 55. The cache server 51 is connected to the Internet 25.
[0111]
The cache server 51 has a global IP address. Further, the cache server 51 acquires information such as contents from the contents server 40 or the like via the Internet 25 in accordance with a request from the user terminal 19, and temporarily stores the information.
The cache server 51 holds, as a table, operation schedule information for each train at a station where the cache server 51 is installed, that is, information on an entry line number and a stop position of each vehicle. It is assumed that the content held by the content server 40 can be obtained by specifying a URL.
[0112]
As shown in FIG. 11, a download server 35 is connected to the Internet 25 in this embodiment. The download server 35 constitutes a portal site for providing a download service to the user terminals 19 on the train.
[0113]
In addition, the download server 35 receives input of train information and the like. Further, the download server 35 holds, as a table, the correspondence between each station and the IP address of the cache server 51 installed therein. It is assumed that the URL indicating the download server 35 is known.
In this embodiment, it is assumed that a wireless tag is attached to a wall or a ceiling in a train, and information of a train number of the train and a vehicle number of each vehicle is input to the user terminal 19 from the wireless tag. I have. Of course, it is also possible to display the train number and the vehicle number on a guide plate installed instead of the wireless tag, and to input the train number and the vehicle number to the user terminal 19 by an input operation by the user.
[0114]
In order to implement the present invention, a function of downloading content from the content server 40 on behalf of the user terminal 19 outside the train is required, but this function may be provided in the cache server 51 installed at each station. Alternatively, it may be provided in the download server 35.
First, the operation of the system will be described in the case where a function of downloading content from the content server 40 as a proxy for the user terminal 19 is provided in the cache server 51.
[0115]
The user specifies the URL of the content to be used for download, and accesses the download server 35 from the user terminal 19 via the mobile phone network 20.
The download server 35 requests the user terminal 19 to input a next stop station (or a station where downloading is desired) as a station where the user terminal 19 is to receive the content.
[0116]
As a response to this request, the user terminal 19 transmits information on the next stop station. When receiving the information of the next stop station from the user terminal 19, the download server 35 notifies the user terminal 19 of the IP address of the cache server 51 existing at the next stop station.
[0117]
The user terminal 19 can transmit a packet such as a download request to the cache server 51 using the IP address received from the download server 35.
Specifically, the user terminal 19 includes the MAC (Media Access Control) address, the train number, and the vehicle number information of the wireless LAN communication device 61 of the user terminal 19 that is the request source, and sends the IP address of its own station to the source IP address. Then, a packet having the IP address of the destination cache server 51 as the destination address is transmitted via the mobile phone network 20.
[0118]
In this embodiment, the session management table 52 held in the cache server 51 is configured as shown in FIG.
When receiving the packet from the user terminal 19, the cache server 51 stores the MAC address, train number, and vehicle number information of the wireless LAN communication device 61 connected to the requesting user terminal 19 in the corresponding item of the session management table 52. Write to. In the source IP address of the session management table 52, the IP address of the requesting user terminal 19 (attached to the mobile phone network), that is, the source IP address of the received IP packet is written.
[0119]
Next, the requesting user terminal 19 encapsulates an IP packet (the source IP address is the IP address of the requesting user terminal 19 and the destination IP address is the IP address of the content server 40) for requesting the content to the content server 40. A packet is generated and transmitted to the Internet 25 via the mobile phone network 20. The source IP address of the encapsulated packet is the IP address of the requesting user terminal 19, and the destination IP address is the IP address of the cache server 51.
[0120]
The encapsulated packet is received by the cache server 51. The cache server 51 decapsulates the received packet and extracts the packet contained therein.
Then, the incoming / outgoing IP address and the incoming / outgoing logical port number of the extracted IP packet are written in the corresponding items of the session management table 52 (see FIG. 9). In this case, the originating IP address is the IP address of the requesting user terminal 19, and the destination IP address is the IP address of the content server 40.
[0121]
Further, the cache server 51 rewrites the originating IP address of the extracted IP packet to its own IP address, and sends the IP packet to the Internet 25. In some cases, it may be necessary to rewrite the destination logical port number.
A response such as ACK is returned from the destination content server 40 to the IP packet transmitted by the cache server 51. As a result, the downlink port number is determined, and the cache server 51 writes the information in the corresponding item of the session management table 52.
[0122]
Further, the content server 40 transmits the information of the requested content to the cache server 51 via the Internet 25.
When the cache server 51 receives the content information transmitted from the content server 40, the cache server 51 specifies the communication (session) by referring to the upper and lower logical port number column and the destination address column in the session management table 52, and receives the information. The content is stored, and a pointer indicating the storage area is written in the session management table 52.
[0123]
The procedure for transferring the content acquired by the cache server 51 to the requesting user terminal 19 is as follows.
The cache server 51 specifies the wireless LAN base station 55 corresponding to the position of the request source for the request for which the content acquisition from the content server 40 has been completed. That is, the train number and the vehicle number are acquired from the session management table 52, and the train entry number and the stop position information of the train are acquired by referring to the operation schedule information of the train at the station. In other words, it specifies the home where the vehicle on which the requester of the content is riding stops.
[0124]
Based on this stop position, the cache server 51 selects one wireless LAN base station 55 that can communicate with the user's wireless LAN communication device 61 in the requesting train.
Then, the cache server 51 transmits the contents and the contents of the session management table 52 to the specific secondary cache device 56 corresponding to the selected wireless LAN base station 55. The storage area column of the session management table 52 to be transmitted is changed to the contents corresponding to the storage area on the secondary cache device 56.
[0125]
When the train enters the platform of the station, the wireless LAN base station 55 on the home side and the wireless LAN communication device 61 in the train automatically detect that they have entered the wireless LAN communication area, respectively, and establish a wireless link. I do.
In this embodiment, there is no dedicated antenna on the train, and there is a possibility that the distance between the wireless LAN communication device 61 and the wireless LAN base station 55 may be large. Therefore, the wireless LAN communication device 61 is, for example, 2.4 GHz. A general wireless LAN device using a wireless frequency of a band or a 5 GHz band is used.
[0126]
The secondary cache device 56 has a global IP address, and assigns the global IP address to the requesting user terminal 19 existing in the stopped train by dynamic control. At this time, a table that holds the correspondence between the MAC address of the wireless LAN and the assigned IP address in the session management table 52 is generated.
[0127]
Thereafter, the secondary cache device 56 transmits the content held by itself to the user terminal 19 via the wireless LAN base station 55 by IP communication.
At this time, the content read from the storage area in the session management table 52 needs to be sent to the user terminal 19 having the MAC address of the wireless LAN on the session management table 52. The IP address corresponding to the MAC address of the corresponding wireless LAN is referred to as the destination IP address and transmitted with reference to the table holding the correspondence relationship of the wireless LAN.
[0128]
Thus, the requested content is transferred to the requesting user terminal 19 via the wireless LAN. When the transfer is completed, the table holding the correspondence between the MAC address of the wireless LAN and the assigned IP address is deleted.
Next, an operation when the download server 35 acquires content from the content server 40 on behalf of the user terminal 19 will be described.
[0129]
The requesting user specifies the URL and accesses the download server 35 from the user terminal 19 via the mobile phone network 20.
The download server 35 includes a next stop station (or a station where downloading is desired), which is a station used when transferring the content to the user terminal 19, the MAC address of the wireless LAN communication device 61 in the user terminal 19 of the request source, and the train number. And input of the vehicle number to the user terminal 19.
[0130]
In this example, the download server 35 manages a session management table (corresponding to 52) as shown in FIG.
When the user terminal 19 transmits the information requested to be input from the download server 35, the download server 35 receives the information, stores the next stop station, and stores the wireless LAN MAC address and the train number of the requesting user terminal 19. And the vehicle number are written in the corresponding fields of the session management table, and the IP address (attached to the mobile phone network) of the requesting user terminal 19, that is, the source IP address of the received IP packet is written in the field of the source IP address. .
[0131]
Next, the requesting user terminal 19 sends an IP packet (the originating address is the IP address of the requesting user terminal 19 and the destination address is the IP address of the content server 40) for requesting the content from the content server 40. It generates an encapsulated packet and sends it out to the Internet 25 via the mobile phone network 20. The source IP address of this packet is the IP address of the requesting user terminal 19, and the destination IP address is the IP address of the download server 35.
[0132]
Upon receiving the packet from the user terminal 19, the download server 35 removes the encapsulation and extracts the inside IP packet, and sets the incoming / outgoing IP address and incoming / outgoing logical port number of the extracted IP packet in the outgoing / Write to the address area and the upstream / outgoing logical port number area.
Then, the download server 35 rewrites the originating IP address of the extracted packet to the IP address of the download server 35 and transmits the IP packet. In some cases, it is necessary to change the destination logical port number.
[0133]
The IP packet transmitted by the download server 35 is received by the content server 40, and the content server 40 returns a response such as ACK to the download server 35.
As a result, the downlink logical port numbers are determined, and this information is written in the corresponding column of the session management table.
[0134]
The content server 40 transmits the information of the requested content to the download server 35 via the Internet 25 in accordance with the request of the IP packet received from the download server 35.
Upon receiving the content information from the content server 40, the download server 35 specifies the communication (session) by referring to the contents of the upper and lower logical port number column and the destination address column on the session management table, and identifies the received content. At the same time, the information of the pointer indicating the storage area is written in the session management table.
[0135]
The download server 35 obtains the IP address of the cache server 51 existing at the next stop station (or the download desired station) of the content request source with reference to the contents of the table held by itself.
Then, the download server 35 transmits the contents of the session management table and the obtained contents to the destination (cache server 51) of the obtained IP address via the Internet 25. The storage area column of the session management table to be transmitted is empty.
[0136]
The cache server 51 receives and stores the information transferred from the download server 35, and writes information of a pointer indicating its own content storage area in the storage area column of the session management table.
The transfer of the content from the cache server 51 to the user terminal 19 is the same as the operation described above.
[0137]
【The invention's effect】
As described above, according to the present invention, a content download service from the Internet or the like can be provided to a user on a train, and the content can be efficiently transferred.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration example of a system.
FIG. 2 is a block diagram showing a configuration of a train device.
FIG. 3 is a flowchart showing the operation of the scheduler.
FIG. 4 is a flowchart showing an operation of the cache server.
FIG. 5 is a schematic diagram showing a configuration of an IP address management table on a scheduler.
FIG. 6 is a schematic diagram showing a configuration of a download request IP packet.
FIG. 7 is a schematic diagram showing a configuration of an encapsulated download request IP packet.
FIG. 8 is a schematic diagram showing a configuration (1) of a session management table on a cache server.
FIG. 9 is a schematic diagram showing a configuration (2) of a session management table on a cache server.
FIG. 10 is a plan view showing an arrangement example of a system.
FIG. 11 is a block diagram illustrating a configuration example of a system.
[Explanation of symbols]
11 train
12 In-vehicle antenna
13 In-vehicle antenna
15 In-car server
16 Wireless devices for mobile phones
17 Wireless device for wireless LAN
18 Wireless LAN base station
19 User terminal
20 Mobile phone network
25 Internet
30 scheduler
31 Train management table
32 IP address management table
33 Interface
35 Download server
40 Content Server
41 Content DB
50 stations
51 Cache Server
52 Session Management Table
55 wireless LAN base station
56 Secondary cache device
61 Wireless LAN communication device
62 Mobile phone communication device

Claims (15)

In a train download service system used to download content requested from any terminal present in the train from a content server connected to a predetermined network and provide the content to the terminal,
Station station wireless communication means that is installed at each of a plurality of stations and is capable of wireless communication with the terminal or onboard server in the train while the train is present on the premises of each station,
Proxy download means connected to the station premises wireless communication means, accessing a corresponding content server as a proxy of a request source according to a download request from the terminal or the in-vehicle server, and acquiring and storing requested content;
Data acquisition station identification means for identifying a station to acquire the data requested by the terminal or the in-vehicle server,
Content transfer means for transferring the content obtained by the proxy download means to the terminal or the in-vehicle server via the station premises wireless communication means belonging to the station specified by the data acquisition station specifying means. Download service system in the train. In a train download service system used to download content requested from any terminal present in the train from a content server connected to a predetermined network and provide the content to the terminal,
Station station wireless communication means that is installed at each of a plurality of stations and is capable of wireless communication with the terminal or onboard server in the train while the train is present on the premises of each station,
Proxy download means connected to the station premises wireless communication means, accessing a corresponding content server as a proxy of a request source according to a download request from the terminal or the in-vehicle server, and acquiring and storing requested content;
Request transfer means for receiving a download request from the terminal or the in-vehicle server via a wide area wireless communication means having a wider communicable range than the station premises wireless communication means, and transferring the received download request to the proxy download means When,
Data acquisition station identification means for identifying a station to acquire the data requested by the terminal or the in-vehicle server,
Content transfer means for transferring the content obtained by the proxy download means to the terminal or the in-vehicle server via the station premises wireless communication means belonging to the station specified by the data acquisition station specifying means. Download service system in the train. In a train download service system used to download content requested from any terminal present in the train from a content server connected to a predetermined network and provide the content to the terminal,
Station station wireless communication means that is installed at each of a plurality of stations and is capable of wireless communication with the terminal or onboard server in the train while the train is present on the premises of each station,
A download request from the terminal or the in-vehicle server is received through the wide area wireless communication means having a wider communicable range than the station premises wireless communication means, and a content server corresponding to a request source proxy according to the received download request. , A proxy download means for acquiring and storing requested content,
Data acquisition station identification means for identifying a station to acquire the data requested by the terminal or the in-vehicle server,
Content transfer means for transferring the content obtained by the proxy download means to the terminal or the in-vehicle server via the station premises wireless communication means belonging to the station specified by the data acquisition station specifying means. Download service system in the train. In the train download service system according to any one of claims 1, 2, and 3,
A train information holding means for holding a train number for specifying each train and operation schedule information of each train is further provided,
The data acquisition station identification unit identifies a next stop station of the corresponding train based on the train number included in the received information and the content of the information held by the train information holding unit. Download service system. In the train download service system according to any one of claims 1, 2, and 3,
A content storing means for storing the content obtained by the proxy download means is arranged at each of a plurality of stations, and station information holding means for holding a correspondence relationship between each content storing means and each station is further provided. Download service system in the train. In the train download service system according to any one of claims 1, 2, and 3,
The in-vehicle download service system, wherein the in-vehicle server transmits information of a corresponding train number together with the download request. In the train download service system according to claim 2 or claim 3,
The download service system in a train, wherein the wide area wireless communication means performs communication using a wireless line of a mobile phone network. In the train download service system according to claim 7,
A download service system in a train, wherein at least one of the proxy download unit, the request transfer unit, and the data acquisition station specifying unit is provided with a mobile phone network communication unit for connecting to a mobile phone network. In the train download service system according to any one of claims 1, 2, and 3,
The download service system in a train, wherein the data acquisition station identification means holds address information of at least one of an in-vehicle server and a terminal in each train. In the train download service system according to any one of claims 1, 2, and 3,
A download service system in a train, wherein at least one of the in-vehicle server and the terminal in each train forms a part of a local IP network. In the train download service system according to any one of claims 1, 2, and 3,
The download service system in a train, wherein the content transfer means holds information of a MAC address or an IP address used when at least one of an in-vehicle server and a terminal in the train performs wireless communication. In the train download service system according to any one of claims 1, 2, and 3,
The download service system in a train, wherein the content transfer unit holds information indicating a correspondence between a train number and an incoming line number of each station or a correspondence between a vehicle number and a stop position. In the train download service system according to claim 12,
A plurality of the station premises wireless communication means are arranged at different places in the station yard of each station, and the content transfer means selectively uses one of the plurality of station premises wireless communication means to store the corresponding content. A download service system in a train, wherein the download service is transmitted to a terminal or the in-vehicle server. A plurality of wireless communication devices installed in the station premises, a content server connected to the wireless communication device via a network, wireless communication between the wireless communication device installed in the train and a terminal in the train or In a train download service system including a train wireless communication device capable of communicating with a train server,
Proxy download means for downloading and holding predetermined content from the content server,
Communication device selection means for selecting one of the plurality of wireless communication devices;
A content transfer unit that transfers the content obtained by the proxy download unit to the terminal or the in-vehicle server in the train via the wireless communication device selected by the communication device selection unit. Download service system. A wireless communication device installed in the station premises, a content server connected to the wireless communication device via a network, a wireless communication between the wireless communication device installed in the train, and a terminal or in-vehicle server in the train In a train download service system comprising a train wireless communication device capable of communicating with
A schedule management unit for selecting a station to be used for download according to a predetermined schedule, and transmitting a download request to the selected station;
A proxy download unit arranged at each station, for acquiring and storing content from the content server according to a download request from the schedule management unit;
Content download means for transferring the content obtained by the proxy download means to a terminal in a train or an in-car server via the wireless communication device.

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