JP4544046B2 - Wireless VoIP system, wireless base station apparatus, and authentication management control method used therefor - Google Patents

Description

  The present invention relates to a wireless VoIP system, a wireless base station apparatus, and an authentication management control method used therefor, and more particularly, to an authentication management control method for VoIP (Voice over Internet Protocol) used in a wireless LAN (Local Area Network).

  Conventionally, as a train radio system, a plurality of in-vehicle terminals are connected to an in-vehicle server provided in the train, and an information providing system on the ground is connected to the in-vehicle server via wireless communication. There is a system that takes out and outputs a service required by a passenger from an information providing system via an in-vehicle server based on the operation (for example, see Patent Document 1).

  In this system, an Internet server connected to an external Internet is provided in the information providing system, and each in-vehicle terminal activates the Internet server via the in-vehicle server based on the operation of the passenger, and the target Web is transmitted via the Internet. Searching for sites.

  Other train radio systems include a communication network, a mobile communication device that executes an on-board communication program, a mobile service device that executes an on-board business program, a train radio system, a train radio central station, Station wireless LAN, station network, base station, mobile phone network, host, and terrestrial communication server, users are aware of the communication transmission method and communication status in communication with mobile units There is also a system that makes it possible to perform seamless communication without the need (see, for example, Patent Document 2).

  Further, as another train radio system, a DHCP (Dynamic Host) that manages IP (Internet Protocol) addresses of a mobile station that is a railway vehicle equipped with an in-vehicle LAN system and a plurality of LAN terminals constituting the in-vehicle LAN system. IP address setting requests from a plurality of LAN terminals of a mobile station by connecting a configuration protocol server) and a ground station having a TTCS (Total Traffic Control System) that manages an operation state including a train time. On the other hand, a system in which a DHCP server sets an IP address specifying an IP address valid period (IP address lease time) based on train train time information managed by TTCS and notifies a plurality of LAN terminals of a mobile station Also (for example, see Patent Document 3).

  On the other hand, as a network connection service in a long-distance train, a passenger terminal, an AP (wireless LAN access point), a RADIUS (Remote Authentication Dial-In User Service) server, a DHCP server, a WEB server, a DNS (Domain Name System) server , PROXY (proxy) server, customer database, in-train customer database, customer management terminal, in-train customer management terminal, push type information distribution server, music image distribution server, wireless transmission / reception device, media conversion device, cable LAN and wireless LAN There is also a system in which an in-train network is configured by connecting with each other, and the in-train network is connected to the Internet by a wireless transmission / reception device or a media conversion device (for example, see Patent Document 4 ).

  The software-based wireless infrastructure system includes a driver that communicates with a network stack and a network interface card (NIC), and a station server that communicates with a station driver and an 802.1X supplicant or 802.1X authenticator. There is a system (see, for example, Patent Document 5).

  In this system, each NIC provides station and / or access point function support. The driver drops the received packet if the packet is not authenticated and associated. Packets that are fragmented or encrypted are defragmented and decrypted. The association manager is used with the configuration table manager to associate stations and access points via management packets.

  Furthermore, in a mobile communication system, it is possible to follow when a mobile node moves at a high speed, improving the use efficiency of network resources and reducing the data transmission / reception efficiency without changing the existing network configuration. An improvement method has been proposed (see, for example, Patent Document 6).

  In the above mobile communication system, the mobile node communicating with the access router of the network detects a change in the connection link, and the mobile node indicates to the other access router the destination of the mobile node based on the change. A change request is transmitted for the care-of address, and the branch router 4 generates a cache in which the care-of address before movement is rewritten with the care-of address after movement included in the change request message. The packet addressed to the care-of address is received by proxy and transferred to the care-of address after movement.

  Furthermore, as an in-train download service system, there has been proposed a system that can provide efficient access at a low cost when a user on the train accesses the Internet or the like (for example, Patent Document 7). reference).

  In this system, station-premises wireless communication means installed at multiple stations and capable of wireless communication with terminals in a train or in-vehicle servers, and download requests from terminals or in-vehicle servers connected to station-premises wireless communication means Access to the corresponding content server as a proxy according to the above, means for acquiring and storing the requested content, data acquisition station specifying means for specifying the station from which the terminal or in-vehicle server acquires the data requested, and proxy download Content transfer means is provided for transferring the acquired content to a terminal or in-vehicle server via a station-premises wireless communication means belonging to the station specified by the data acquisition station specifying means.

JP 2001-222603 A JP 2002-111702 A Japanese Patent Laid-Open No. 10-2762173 JP 2004-173179 A JP 2004-180324 A JP 2004-040581 A JP 2004-038242 A

  In the conventional train radio system described above, when a segment moves to another wireless LAN base station (access point) when the wireless terminal moves on the train, the segment is switched to reacquire the IP address from DHCP. Since the IP address changes, it is not possible to perform continuous calls using VoIP.

  Further, in the conventional train radio system, there is a limit to the distance to extend the segment, so the IP address is used as it is in the moving train radio terminal, so the segments connected to all access points cannot be the same. There is a problem.

  In the prior art described in each of the above-mentioned Patent Documents 1 to 7, there is no mention of a method for dealing with the fact that continuous VoIP calls cannot be made due to the change of the IP address due to the switching of the segments. Each cannot be solved.

  Accordingly, an object of the present invention is to solve the above-described problems, and to maintain a call (VoIP channel) even when an access point is switched as a wireless terminal moves in a train. It is to provide a station apparatus and an authentication management control method used for them.

A wireless VoIP system according to the present invention includes a wireless terminal that performs wireless LAN (Local Area Network) connection in a train, a RADIUS (Remote Authentication Dial-In User Service) server for at least connection authentication of the wireless terminal, and the wireless terminal A DHCP (Dynamic Host Configuration Protocol) server for delivering an IP (Internet Protocol) address to the wireless terminal, and a SIP (Session Initiation Protocol 3) and SIP (Session Initiation Protocol 3) for VoIP (Voice over Internet Protocol) connection control of the wireless terminal. ) Wireless Vo including a center station device connecting a switch to the same segment An IP system,
The DHCP server has a function of paying out an IP address of the same segment as the center station device for the wireless terminal,
A radio base station apparatus including an access controller connected to access points arranged at regular intervals along a track along which the train moves, and an L3 switch for connecting to an L3 switch of the center station apparatus in a tunnel mode; Prepared,
Based on the IP address of the same segment as the center station apparatus acquired from the DHCP server, the center station apparatus is controlled by the SIP server via the access point and the radio base station apparatus. It is possible to make a call with the VoIP terminal.

A radio base station apparatus according to the present invention includes a radio terminal that performs a wireless LAN (Local Area Network) connection in a train, a RADIUS (Remote Authentication Dial-In User Service) server for at least connection authentication of the radio terminal, and the radio A DHCP (Dynamic Host Configuration Protocol) server for delivering an IP (Internet Protocol) address to a terminal, and a SIP (Session Initiation Protocol) and SIP (Session Initiation Protocol) for VoIP (Voice over Internet Protocol) connection control of the wireless terminal. 3) A wireless VoIP system including a center station device that connects the switch to the same segment. A wireless base station device used in the system,
An access controller connected to access points arranged at regular intervals along the track on which the train moves, and an L3 switch for connecting to the L3 switch of the center station device in a tunnel mode,
The wireless terminal is controlled via the access point, the access controller, and the L3 switch under the control of the SIP server, based on the IP address of the same segment as the center station device that has been issued from the DHCP server. Communication with the VoIP terminal in the center station apparatus is possible.

An authentication management control method according to the present invention includes a wireless terminal that performs wireless LAN (Local Area Network) connection in a train, a RADIUS (Remote Authentication Dial-In User Service) server for connection authentication of at least the wireless terminal, and the wireless terminal. A DHCP (Dynamic Host Configuration Protocol) server for delivering an IP (Internet Protocol) address to a terminal, and a SIP (Session Initiation Protocol) and SIP (Session Initiation Protocol) for VoIP (Voice over Internet Protocol) connection control of the wireless terminal. 3) Wireless VoIP including a center station device that connects the switch to the same segment An authentication management control method used in the system,
The DHCP server has a function of paying out an IP address of the same segment as the center station device for the wireless terminal,
The radio base station apparatus is provided with an access controller connected to access points arranged at regular intervals along the track on which the train moves, and an L3 switch for connecting to the L3 switch of the center station apparatus in a tunnel mode. ,
Based on the IP address of the same segment as the center station apparatus acquired from the DHCP server, the center station apparatus is controlled by the SIP server via the access point and the radio base station apparatus. It is possible to make a call with the VoIP terminal.

  That is, in the wireless VoIP (Voice over Internet Protocol) system of the present invention, the access controller in each radio base station apparatus connects to the intranet via the L3 (Layer 3) switch, and in the tunnel mode with the L3 switch in the center station. Configured to connect.

  When the train radio terminal in the train continues to talk, even when the access point connected so far by moving the train is switched to an access point connected to another segment, The IP address that has been used so far is used without acquiring the IP (Internet Protocol) address again from DHCP (Dynamic Host Configuration Protocol).

  As described above, in the wireless VoIP system of the present invention, the access controller connected to the access point tunnels to the center station via the L3 switch, so that it appears as if there is a train wireless terminal in the segment of the center station. Therefore, even if the wireless terminal in the train moves and the access point is switched, it is possible to maintain a call (VoIP channel).

  With the configuration and operation described below, the present invention has an effect that a call (VoIP channel) can be maintained even when an access point is switched as a wireless terminal moves in a train. It is done.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a wireless VoIP system according to an embodiment of the present invention. In FIG. 1, a wireless VoIP system according to an embodiment of the present invention has access points 41 to 44 connected to a train wireless terminal 5 in a moving train A and a wireless LAN (Local Area Network) at regular intervals along the track. ing.

  In the wireless VoIP system according to an embodiment of the present invention, the access controllers 22 and 32 and the L3 (Layer 3) switches 21 and 31 to which a plurality of access points 41 to 44 are connected are respectively connected to the radio base station apparatuses 2 and 3. Has been deployed.

  Furthermore, the wireless VoIP system according to an embodiment of the present invention includes a VoIP terminal 11 that communicates with the center wireless communication device 5 at the center station device 1 and a RADIUS (Remote Authentication Dial-In User Service) for connection authentication of the train wireless terminal 5. The server 12, a DHCP (Dynamic Host Configuration Protocol) server 13 for delivering an IP address to the train radio terminal 5, and a SIP (Session Initiation Protocol) server 14 for VoIP connection control are connected to the same segment, and the L3 switch 15 is connected to another segment via 15.

  The access controllers 22 and 32 of the radio base station apparatuses 2 and 3 are connected to the intranet 100 via the L3 switches 21 and 31 and are connected to the L3 switch 15 of the center station apparatus 1 in the tunnel mode. The access controllers 22 and 32 connected to the access points 41 to 44 tunnel to the center station apparatus 1 via the L3 switches 21 and 31, so that the train radio terminal 5 exists in the segment of the center station apparatus 1. Voice communication can be continued.

  2 to 4 are sequence charts showing the operation of the wireless VoIP system according to an embodiment of the present invention. The operation of the wireless VoIP system according to an embodiment of the present invention will be described with reference to FIGS.

  First, a procedure for switching the connection destination of the train radio terminal 5 from the access point 41 connected to the same access controller 22 to the access point 42 will be described.

  The train radio terminal 5 is first connected to the access point 41 that is close by the conventional wireless LAN connection procedure (see a1 in FIG. 2). When a new connection is made, the access controller 22 makes an authentication inquiry to the RADIUS server 12 in the center station device 1 based on the identification information of the train radio terminal 5 (see a2 in FIG. 2). The L3 switch 21 is connected (see a3 in FIG. 2).

  Next, the train radio terminal 5 acquires an IP address from the DHCP server 13 (see a4 in FIG. 2), and then connects the VoIP terminal 11 in the center station apparatus 1 to the VoIP channel under the control of the SIP server 14 (FIG. 2). 2 a5, a6).

  When the train radio terminal 5 moves in the call state (see a7 in FIG. 2) (the train radio terminal 5 moves by the movement of the train A in the call state), the reception level of the access point 41 becomes less than the threshold value. (Refer to a8 in FIG. 2), an access point with a high reception level is searched (see a9 in FIG. 2), and an access point connection recommended access point is inquired to the access controller 22 (see a10 in FIG. 2).

  The access controller 22 notifies the train wireless terminal 5 of the access point 42 to be connected next from the access point 41 connected to the own device (see a11 in FIG. 2). When the state below the threshold of the reception level continues for a certain period of time (see a12 in FIG. 3), the train radio terminal 5 connects to the access point 42 by a wireless LAN connection procedure (see a13 in FIG. 3). In this case, the access controller 22 omits the authentication inquiry to the RADIUS 12, and connects the access point 42 and the L3 switch 21 (see a14 in FIG. 3).

  When the connection between the access point 42 and the L3 switch 21 is completed, the access controller 22 disconnects the access point 41 (see a15 in FIG. 3), and uses the IP address that has been used at the access point 41 as it is. The call is continued (see a16 in FIG. 3).

  Next, a procedure for switching the connection destination of the train radio terminal 5 from the access point 42 connected to the different access controllers 22 and 32 to the access point 43 will be described.

  When the train radio terminal 5 moves in the call state (see b1 in FIG. 4) (the train radio terminal 5 moves by the movement of the train A in the call state), the reception level of the access point 42 becomes less than the threshold value. (Refer to b2 in FIG. 4), an access point with a high reception level is searched (see b3 in FIG. 4), and the access controller 22 is inquired about an access point connection recommended access point (see b4 in FIG. 4).

  When the access point to be connected next is in the access controller 32, the access controller 22 notifies the access controller 32 of the authentication information (including the IP address assigned to the train radio terminal 5) (see b5 in FIG. 4). Is notified to the train radio terminal 5 (see b6 in FIG. 4).

  When the state below the threshold of the reception level continues for a certain period of time (see b7 in FIG. 4), the train wireless terminal 5 connects to the access point 43 by a wireless LAN connection procedure (see b8 in FIG. 4). In this case, the access controller 32 omits the authentication inquiry to the RADIUS 12, and connects the access point 43 and the L3 switch 31 (see b9 in FIG. 4).

  When the connection between the access point 43 and the L3 switch 31 is completed (see b10 in FIG. 4), the access controller 22 disconnects the access point 42 (see b11 in FIG. 4) and has been used at the access point 42 so far. The call is continued using the IP address as it is (see b12 in FIG. 4).

  Thus, in the present embodiment, tunneling between the center station apparatus 1 and the base station apparatuses 2 and 3 using the L3 switches 15, 21, and 31 makes it as if the train radio terminal 5 is connected to the segment of the center station apparatus 1. Voice communication can be continued as if there is.

  In this embodiment, the same IP address is used in the access points 43 and 44 in different segments, and re-acquisition of the IP address between new DHCPs can be omitted.

  Further, in the present embodiment, the authentication inquiry at the time of connection of the access points 41 to 44 can be omitted by taking over the authentication information between the access controllers 22 and 32.

  Furthermore, in the present embodiment, by using the SIP server 14 in the center station apparatus 1, the center station apparatus 1, the radio base station apparatuses 2 and 3, and the access points 41 to 44 can be connected even between the train radio terminals 5. The call can be made via

  Although the present invention describes the train radio terminal in the above embodiment, it can be applied to direct connection with a VoIP terminal by replacing a mobile phone that moves at high speed in the field with a VoIP terminal.

1 is a block diagram illustrating a configuration of a wireless VoIP system according to an embodiment of the present invention. 3 is a sequence chart illustrating an operation of a wireless VoIP system according to an embodiment of the present invention. 3 is a sequence chart illustrating an operation of a wireless VoIP system according to an embodiment of the present invention. 3 is a sequence chart illustrating an operation of a wireless VoIP system according to an embodiment of the present invention.

Explanation of symbols

1 Center station equipment
2, 3 Radio base station equipment
5 Train radio terminal
11 VoIP terminal
12 RADIUS server
13 DHCP server
14 SIP server 15, 21, 31 L3 switch 22, 32 Access controller 41-44 Access point
100 Intranet

Claims (12)

A wireless terminal that performs wireless LAN (Local Area Network) connection in a train, a RADIUS (Remote Authentication Dial-In User Service) server for connection authentication of the wireless terminal, and an IP (Internet Protocol) address for the wireless terminal A DHCP (Dynamic Host Configuration Protocol) server for distribution, a SIP (Session Initiation Protocol) server for VoIP (Voice over Internet Protocol) connection control of the wireless terminal, and an L3 (Layer 3) switch in the same layer 3 switch A wireless VoIP system including a center station device that performs
The DHCP server has a function of paying out an IP address of the same segment as the center station device for the wireless terminal,
A radio base station apparatus including an access controller connected to access points arranged at regular intervals along a track along which the train moves, and an L3 switch for connecting to an L3 switch of the center station apparatus in a tunnel mode; Have
Based on the IP address of the same segment as the center station apparatus acquired from the DHCP server, the center station apparatus is controlled by the SIP server via the access point and the radio base station apparatus. A wireless VoIP system capable of making a call with an internal VoIP terminal.   A wireless terminal connected to the access point under the wireless base station apparatus and making a call with the VoIP terminal is connected in a tunnel mode when moving to an access point under another wireless base station apparatus. 2. The wireless VoIP system according to claim 1, wherein the telephone conversation with the VoIP terminal is continued using an IP address of the same segment as the center station apparatus.   The access controller makes an authentication inquiry to the RADIUS server based on the identification information of the wireless terminal, and when authenticated, between the access point connected to the wireless terminal and a wireless LAN and the L3 switch in the own apparatus. 3. The wireless VoIP system according to claim 1, wherein the wireless VoIP system is connected.   4. The wireless VoIP system according to claim 1, wherein the access controller notifies an access point to be connected next in response to an inquiry from the wireless terminal. A wireless terminal that performs wireless LAN (Local Area Network) connection in a train, a RADIUS (Remote Authentication Dial-In User Service) server for connection authentication of the wireless terminal, and an IP (Internet Protocol) address for the wireless terminal A DHCP (Dynamic Host Configuration Protocol) server for distribution, a SIP (Session Initiation Protocol) server for VoIP (Voice over Internet Protocol) connection control of the wireless terminal, and an L3 (Layer 3) switch in the same layer 3 switch Base station equipment used in a wireless VoIP system including a center station device Where
An access controller connected to access points arranged at regular intervals along the track on which the train moves, and an L3 switch for connecting to the L3 switch of the center station device in a tunnel mode,
The wireless terminal is controlled via the access point, the access controller, and the L3 switch under the control of the SIP server, based on the IP address of the same segment as the center station device that has been issued from the DHCP server. A radio base station apparatus capable of making a call with a VoIP terminal in the center station apparatus.   When a wireless terminal connected to a wireless LAN connected to an access point under its own device and making a call with the VoIP terminal is switched to an access point under the control of another device by movement, at least the wireless terminal is connected to an access controller of the other device 6. The radio base station apparatus according to claim 5, wherein the authentication information is notified.   The access controller makes an authentication inquiry to the RADIUS server based on the identification information of the wireless terminal, and when authenticated, between the access point connected to the wireless terminal and a wireless LAN and the L3 switch in the own apparatus. The radio base station apparatus according to claim 5, wherein the radio base station apparatus is connected.   8. The radio base station apparatus according to claim 5, wherein the access controller notifies an access point to be connected next in response to an inquiry from the radio terminal. A wireless terminal that performs wireless LAN (Local Area Network) connection in a train, a RADIUS (Remote Authentication Dial-In User Service) server for connection authentication of the wireless terminal, and an IP (Internet Protocol) address for the wireless terminal A DHCP (Dynamic Host Configuration Protocol) server for distribution, a SIP (Session Initiation Protocol) server for VoIP (Voice over Internet Protocol) connection control of the wireless terminal, and an L3 (Layer 3) switch in the same layer 3 switch Management control method for use in a wireless VoIP system including a center station device Because
The DHCP server has a function of paying out an IP address of the same segment as the center station device for the wireless terminal,
The radio base station apparatus is provided with an access controller connected to access points arranged at regular intervals along the track on which the train moves, and an L3 switch for connecting to the L3 switch of the center station apparatus in a tunnel mode. ,
Based on the IP address of the same segment as the center station apparatus acquired from the DHCP server, the center station apparatus is controlled by the SIP server via the access point and the radio base station apparatus. An authentication management control method characterized in that communication with a VoIP terminal is possible.   A wireless terminal connected to the access point under the wireless base station apparatus and making a call with the VoIP terminal is connected in a tunnel mode when switching to an access point under another wireless base station apparatus by movement. The authentication management control method according to claim 9, wherein a call with the VoIP terminal is continued using an IP address in the same segment as the center station apparatus.   The access controller makes an authentication inquiry to the RADIUS server based on the identification information of the wireless terminal, and when authenticated, between the access point connected to the wireless terminal and a wireless LAN and the L3 switch in the own apparatus. The authentication management control method according to claim 9, wherein the authentication management control method is connected.   The authentication management control method according to claim 9, wherein the access controller notifies an access point to be connected next in response to an inquiry from the wireless terminal.

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