JP4992508B2 - COMMUNICATION CONTINUING METHOD, SYSTEM, AND PROGRAM - Google Patents

Description

  The present invention relates to a communication continuation method, and more particularly to a communication continuation system for continuing communication between terminals capable of switching between wireless LAN communication and external line communication by a portable communication terminal.

  In recent years, wireless LAN (hereinafter referred to as WLAN) and mobile (GSM, WCDMA, etc.) terminals with dual functions (hereinafter referred to as dual terminals) have been used, and public wireless LAN hotspots and WLANs have been used within enterprises. Voice services for ISPs and companies that support external communication using mobile devices when calling or going out have started. Techniques for switching communication between such dual terminals are disclosed in Patent Documents 1, 2, and 3.

  In the future, it is expected that a so-called ubiquitous service with a single telephone terminal can be enjoyed from anywhere at home, at work or on the go. Under such trends, 3GPP is currently standardizing VCC (Voice Call Continuity) with the aim of providing voice seamless communication services between 3G circuit switched networks and IP Multimedia Subsystem (hereinafter referred to as IMS). In VCC, when IMS is used, WLAN is assumed to be used as an access technology.

  As shown in FIG. 13, the VCC service is supported by a system including MGCF 30, MGW 40, CSCF 20, and VCC APL 25 constituting IMS in addition to 3G CS. In the VCC, for example, if the dual terminal user B is out of the WLAN area during a call between the dual terminal A and B users using the WLAN, the dual terminal B determines that the handover from the WLAN to the 3G CS is performed (HO). Then, when the terminal B makes a call from the 3GCS side to the VCC APL 25 that supports the VCC function in the sequence shown in FIG. 14, the call signal is passed to the MSC 50 --- MGCF 30 (2. in FIG. 14). When receiving the call signal, the MGCF 30 issues an INVITE message with destination = VCC APL 25 to the CSCF 20 (5 in FIG. 14). The VCC APL 25 that has received the INVITE message via the CSCF 20 recognizes that the terminal B has HOed from 3GCS to the WLAN side, and notifies the partner terminal A that the terminal B has HOed from 3GCS to the WLAN. Receiving the notification, partner terminal A switches the destination of the voice packet (RTP packet) to MGW 40 and transmits it. Thereafter, the VCC APL 25 releases the 3GCS line of terminal B. As described above, the voice session between the terminal B and the terminal A is continued.

  In this way, when one of the terminals is out of the WLAN area and is HOed to the 3G CS side while the dual terminals are in the extension, the extension-extension call shifts to a call between the 3G CS and the corporate extension. Originally, in an extension call, both the C plane signal and the voice packet may be closed in the corporate network and processed. However, when the current VCC is simply applied to a corporate VoIP network as it is, the following drawbacks arise.

  In other words, if VCC is applied to a corporate extension system and a voice call continues using 3G CS even if one of the dual terminals leaves the WLAN area during an extension call, it will use the resources of the mobile operator. No extension-The mobile operator must accommodate the C plane signal for extension calls. And even if the mobile operator accommodates the amount of extension traffic that should be free for the company, no matter how much the mobile operator can accommodate the traffic, it is unlikely that a fee will be collected. Is difficult to establish.

  On the other hand, since the C-plane traffic for extension calls is outside the corporate network, it is necessary to add a dedicated line or VPN for accommodating the traffic to the operator network. For this reason, it is necessary for companies to invest some funds for extension calls that should be free.

  In addition, normal WLAN and 3G dual terminals have the ability to make the WLAN and 3G side active at the same time. For this reason, as shown in Fig. 15, if the terminal enters the WLAN area while making a call with 3G CS, the call using 3GCS can be continued, so it is only necessary to disconnect 3GCS after the WLAN side becomes accessible. This makes it possible to achieve seamless HO for audio in a form similar to the traditional Make Before Brake. On the other hand, when the terminal goes out of the WLAN area and HOs to the 3GCS side, a momentary interruption occurs due to the relationship between the timing when the WLAN side cannot receive and the timing when HO goes to the 3GCS side. For this reason, it is required to shorten the call interruption time associated with HO as much as possible. However, in the current VCC, when terminal B HOs from WLAN to 3GCS side, terminal A, which is notified that terminal B has HOed, sends the destination of the voice packet (denoted as RTP packet) from terminal B within the mobile network. It is necessary to switch to MGW. Since this terminal side RTP packet destination switching process occurs, a relatively large voice interruption occurs in a call between terminals A and B.

JP 2004-248291 A JP 2005-341610 A JP 2006-229831 A

  As described above, the issues when applying the VCC mechanism directly to the corporate extension system are summarized as follows. (1) The operator network must handle up to the company extension calls that are not necessarily handled by the current VCC technology for the operator, which may increase the cost burden. (2) Since the extension call goes out of the enterprise network for the enterprise side, it is necessary to newly introduce a secure VPN network. (3) When a dual-terminal user moves away from the WLAN area while handing over the extension-extension call to the other party and handed over to the 3GCS side to shift to a call using a 3GCS line, a relatively large instantaneous interruption occurs in the voice call between the dual terminals. .

  Therefore, an object of the present invention is to provide a communication connection system that improves the inconveniences of the above-described conventional example, and that is particularly low cost, high security, and high user convenience.

Therefore, the communication continuation method according to one aspect of the present invention is:
A wireless LAN control device that performs connection control in a wireless LAN network of a portable communication terminal that can be connected to a wireless LAN network and a cellular phone network, and a portable type that is installed in a cellular phone network and an Internet network connected to the wireless LAN network A communication continuation method for continuing communication between different networks of a portable communication terminal by a connection control device that performs connection control of a communication terminal,
A location registration step in which the wireless LAN control device performs location registration of the portable communication terminal connected to the wireless LAN network with respect to the own device and the connection control device on the Internet network, and stores location registration information in each device;
A state information management step in which the wireless LAN control device detects the communication state of the portable communication terminal and stores and manages it as state information;
When one of the portable communication terminals in communication connection with each other moves in and out of the wireless LAN network, the connection control device and the wireless LAN control device are based on the location registration information and the state information. A communication continuation step for controlling to continue communication between portable communication terminals;
It is characterized by having.

  The state information includes connection destination terminal information of a portable communication terminal in communication connection and network information to which the portable communication terminal is connected.

  In addition, when two portable communication terminals are in communication connection in a wireless LAN network, the communication continuation step is performed when one portable communication terminal exits from the wireless LAN network to the cellular phone network. A calling process in which a portable communication terminal makes a call from the mobile phone network to the other portable communication terminal via the connection control device and the wireless LAN control device, and a call is received from one portable communication terminal A session switching step in which the connection control device makes a call to the wireless LAN control device and the wireless LAN control device that receives the call switches the session so that the communication connection between the one and the other portable communication terminals is continued. It is characterized by that. At this time, in the session switching step, the wireless LAN control device determines the connection destination of the established session of the other portable communication terminal connected to the wireless LAN network as one portable communication in the wireless LAN network. The terminal is switched to one portable communication terminal connected to a cellular phone network via a connection control device.

  When one of the portable communication terminals connected to the mobile phone network and the other portable communication terminal connected to the wireless LAN network are in communication connection, the communication continuation step When the communication terminal enters the wireless LAN network from the mobile phone network, the wireless LAN connection step in which the one portable communication terminal connects to the wireless LAN network, and the wireless LAN control device that has received this connection A session switching step of switching a session so that communication connection between portable communication terminals is continued. At this time, in the session switching step, the wireless LAN control device connects the connection destination of the established session of the other portable communication terminal connected to the wireless LAN network to the mobile phone network via the connection control device. One portable communication device is switched to one portable communication terminal connected to the wireless LAN network.

  According to the above invention, first, when the portable communication terminal is located in the wireless LAN network, the portable communication terminal is connected to the wireless LAN network, registered in the wireless LAN control device, and connected to the Internet network from the wireless LAN control device. The location is also registered in the device. When the portable communication terminal communicates with another portable communication device, a session is established within the wireless LAN network, or a wireless communication with another portable communication terminal connected to the portable telephone network is established. A session is established through the LAN network, the Internet network, and the mobile phone network. That is, the portable communication terminal is connected for communication between the wireless LAN network and the wireless LAN network or between the wireless LAN network and the mobile phone network. At this time, the wireless LAN control apparatus stores and manages state information such as the communication state of the portable communication terminal, for example, which terminal is connected to which network.

  After that, when one portable communication terminal in communication connection moves in and out of the wireless LAN network, for example, one portable communication terminal changes to the cellular phone network from the connection state between the wireless LAN network and the wireless LAN network. If the mobile communication terminal connected to the mobile phone network moves from the connection state between the wireless LAN network and the mobile phone network to the wireless LAN network, the connection control device on the Internet network, The wireless LAN control device continues the communication connection state between the portable communication terminals based on the location registration information and the state information.

  Therefore, in the above invention, the connection of the portable communication terminal to the extension network, which is a wireless LAN network, and other external networks can be switched, and the management of the portable communication terminal in each network can be distinguished. To provide a communication continuation method for a portable communication terminal that can suppress the burden of connection control of a terminal in an unmanaged network by a person who performs network management, is low-cost, secure, and highly convenient for users Can do.

  Further, in the session switching step, the data transmission destination / source in the established session of the other portable communication terminal connected to the wireless LAN network is always one portable communication terminal before and after the session switching. It is characterized by having an address conversion setting step of performing address conversion setting for an address conversion device through which data communicated between one and the other portable communication terminals passes.

  As a result, the data transmission destination / source in the portable communication terminal on the wireless LAN network side is always information representing the other terminal, so that the communication partner moves through the network for the portable communication terminal on the wireless LAN network side. Even so, the movement is concealed. On the other hand, in data communication, since the address representing the data transmission destination / source is converted by the address conversion device, the data communication can be executed reliably. Therefore, it is possible to speed up the switching process at the time of session switching, and it is possible to effectively suppress interruption of the session.

Moreover, the communication continuation system which is the other form of this invention is
A wireless LAN control device that performs connection control in a wireless LAN network of a portable communication terminal that can be connected to a wireless LAN network and a cellular phone network, and a portable type that is installed in a cellular phone network and an Internet network connected to the wireless LAN network A communication continuation system comprising a connection control device for controlling connection of a communication terminal, and continuing communication between different networks of a portable communication terminal,
A wireless LAN control device for registering a location of a portable communication terminal connected to a wireless LAN network to the local device and a connection control device on the Internet network, and storing location registration information in each device; State information management means for detecting the communication state of the type communication terminal and storing and managing it as state information,
Based on the location registration information and the state information when one of the portable communication terminals in communication connection between the connection control device and the wireless LAN control device moves in and out of the wireless LAN network. Communication continuation means for controlling to continue communication between portable communication terminals.

In addition, a wireless LAN control device according to another aspect of the present invention is
A wireless LAN control device for performing connection control in a wireless LAN network of a portable communication terminal connectable to a wireless LAN network and a mobile phone network,
A connection control device for performing location control of a portable communication terminal connected to a wireless LAN network and controlling the connection of the portable communication terminal installed in the internet device connected to the own device and the cellular phone network and the wireless LAN network , And location registration means for storing location registration information in each device;
State information management means for detecting the communication state of the portable communication terminal and storing and managing it as state information;
Continuation of communication that controls communication between portable communication terminals based on state information when one of the portable communication terminals that are in communication with each other moves in and out of the wireless LAN network Means,
It is characterized by having.

Then, when two portable communication terminals are in communication connection in the wireless LAN network, the communication continuation means, when one portable communication terminal exits from the wireless LAN network to the cellular phone network, A portable communication terminal makes a call from the mobile phone network to the other portable communication terminal via the connection control device and the wireless LAN control device, and the connection control device that received this call made a call to the wireless LAN control device. A session switching means for accepting a call and switching the session so that the wireless LAN control device continues the communication connection between the one and the other portable communication terminals;
It is characterized by that. At this time, the session switching means determines the connection destination of the established session of the other portable communication terminal connected to the wireless LAN network from the one portable communication terminal in the wireless LAN network. And switching to one portable communication terminal connected to the cellular phone network.

  Further, when one of the portable communication terminals connected to the cellular phone network and the other portable communication terminal connected to the wireless LAN network are in communication connection, the communication continuation means When the communication terminal enters the wireless LAN network from the cellular phone network, the one portable communication terminal is connected to the wireless LAN network, and the wireless LAN control device that has received this connection is connected between the one and the other portable communication terminals. It is characterized by comprising a session switching means for switching a session so that the communication connection is continued. At this time, the session switching means determines the connection destination of the established session of the other portable communication terminal connected to the wireless LAN network as one portable type connected to the cellular phone network via the connection control device. It is characterized by switching from the communication device to one portable communication terminal connected to the wireless LAN network.

Moreover, the program which is the other form of this invention is:
A wireless LAN control device that performs connection control in a wireless LAN network of a portable communication terminal that can be connected to a wireless LAN network and a cellular phone network.
A connection control device for performing location control of a portable communication terminal connected to a wireless LAN network and controlling the connection of the portable communication terminal installed in the internet device connected to the own device and the cellular phone network and the wireless LAN network , A location registration means for storing location registration information in each device,
State information management means for detecting the communication state of the portable communication terminal and storing and managing it as state information;
Continuation of communication that controls communication between portable communication terminals based on state information when one of the portable communication terminals that are in communication with each other moves in and out of the wireless LAN network Means,
It is characterized by realizing.

  The invention of the system, apparatus, and program having the above-described configuration operates in the same manner as the above-described method invention, and thus the above-described object of the present invention can be achieved.

  Since the present invention is configured and functions as described above, according to this, it is possible to realize the switching of the connection between the portable communication terminal to the extension network, which is a wireless LAN network, and other external networks, and it is possible to secure at a low cost. In addition, it is possible to provide a communication continuation method for a portable communication terminal that is convenient for the user.

  Hereinafter, specific examples of the configuration and operation of the present invention will be described with reference to examples. The portable communication terminal in the following embodiments can connect to a wireless LAN network and perform an internal call within the wireless LAN network and an external line call via the wireless LAN network. It can also be connected to a 3G network to make external calls with other terminals. That is, the portable communication terminal in the present invention is a terminal (hereinafter referred to as a dual terminal) having a dual function of a wireless LAN (hereinafter referred to as WLAN) function and a mobile (such as GSM or WCDMA) function. The present invention is characterized in that communication between different networks of the dual terminal is continued.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing a configuration of the entire communication system, and FIG. 2 is a functional block diagram showing a configuration of devices constituting the system. FIG. 3 is a diagram illustrating an example of data managed by the system. 4 to 8 are explanatory diagrams showing the state of communication control in the system.

[Constitution]
First, as shown in FIG. 1, the dual terminals A and B in this embodiment are located in an in-house WLAN network 400 constructed in a certain company, and an internal extension call via the WLAN access point 15. Is possible. Then, in the WLAN network 400, an in-company session controller 11 (hereinafter referred to as “in-company SIP server”) that controls to enable extension calls between the dual terminals A and B and an outside line call via the WLAN network (hereinafter referred to as “in-company SIP server”) ( Wireless LAN control device).

  Then, the in-company session controller 11 is an extension session controller 110 that provides an extension-extension call for the dual terminals A and B, and, as will be described later, from an extension-extension call to a call that uses an extension-3G CS line, or And a session continuation control unit 111 that supports voice session continuation when a call using the extension-3GCS line is shifted to an extension-extension call. The extension session controller 110 and the session continuation control unit 111 may be configured by a single computer or may be configured by individual computers.

  As shown in FIG. 2, an extension service unit 110a (location registration means) and a SIP transfer unit 110b are constructed by incorporating a predetermined program in the extension session controller 110. Similarly, as shown in FIG. 2, the session continuation control unit 111 incorporates a predetermined program, so that a SIP registration unit 111a (location registration unit), a state management unit 111b (state information management unit), A session continuation processing unit 111c (session switching means (communication continuation means)) is constructed. Further, a session state storage unit 111 d is formed in the storage unit of the session continuation control unit 111. The function of the above configuration will be described in detail later when the operation is described.

  The in-company session controller 11 is connected to an IMS (IP Multimedia subsystem) 300 (Internet network), and communicates with other terminals of the mobile network 100 (mobile phone network) via the IMS 300 from the wireless LAN network 400. It is also possible to do. As shown in FIG. 1, the IMS 300 is equipped with CSCF 20, MGCF 30, and MGW 40. The CSCF 20 functions as a SIP server that performs call control, as will be described later. In addition, 3GCS 200 is formed in mobile network 100 and MSC 50 is equipped. The mobile network 100 is equipped with a base station 60 and an RNC 70 that constitute a 3G RAN. In addition, since the structure which comprises these networks is well-known, the detailed description is abbreviate | omitted.

[Operation]
Next, the operation of the above configuration will be described with reference to FIGS. First, with reference to FIG. 4, an operation example when the dual terminals A and B are powered on in the corporate LAN network 400 and an operation during the extension-extension call of the terminals A and B will be described.

  First, when the dual terminals A and B are turned on in the company, the terminals A and B access the wireless LAN, and the extension session controller 110 of the in-company session controller 11 (in-house SIP server) is connected to the in-company LAN network. SIP registration, which is location registration, is performed (arrows Y1, Y2, location registration process). When the extension session controller 110 (extension service unit 110a) accepts the SIP registration, the extension session controller 110 provides the extension call service to the terminals A and B thereafter.

  The extension session controller 110 (SIP transfer unit 110b) transfers the SIP registration messages of the terminals A and B to the session continuation control unit 111 (arrow Y3). Then, the session continuation control unit 111 performs SIP registration on the SIP server (CSCF) 20 on the IMS 300 side instead of the terminals A and B (arrow Y4, location registration process). When the SIP server (CSCF) 20 (connection control device, communication continuation means) on the IMS side accepts the SIP registration, it can thereafter provide the IMS service to the terminals A and B.

  Thereafter, when a session is established between the terminal A and the terminal B via the extension-extension call under the control of the extension session controller 110 (extension service unit 110a) (arrows Y5 and Y6), the session continuation control unit 111 ( The state management unit 111b) manages state information as shown in FIG. 3 in synchronization with the extension session controller 110 (session state storage unit 111d, state information management step). Specifically, the session continuation control unit 111 uses, as state information, for each session management target terminal (terminals A and B), an IMS registration state and a call state (whether an extension resource is used or a 3GCS line is used). ) (Network information) and call partner information (connection destination terminal information) are stored and managed. For example, when the terminal A and the terminal B are in an extension call, as shown in FIG. 3, the state information indicates that the session management target terminal B uses the extension resource, the call partner terminal is the terminal A, and the terminal A also manages information on the contents of extension-extension calls that use extension resources. Further, this state information is changed and stored when the call state of the terminals A and B is changed.

  As described above, when the terminals A and B are making an extension call with the support of the in-house SIP server 11, the SIP registration state for the IMS-side CSCF 20 is controlled while controlling the extension call between the terminal A and the terminal B. The state of being. Note that the session continuation control unit 111 may be supported by a commonly used B2BUA. Also, extension-extension voice packets (hereinafter referred to as RTP packets) between terminal A and terminal B are handled by the RTP protocol, and IP addresses and port numbers (hereinafter referred to as Port # and RTP packets between terminal A and terminal B are exchanged by E2E (arrow Y6).

  Next, with reference to FIG. 5, an example of operation when the user of the terminal B goes out while making an extension-extension call with the terminal A in the company and continues the call with the terminal A using the 3GCS line will be described. (Communication continuation process). First, when the user of the terminal B goes out while making an extension call with the terminal A (arrow Y6) and leaves the wireless LAN area 400 (arrow Y7), the terminal B hands over from the wireless LAN to 3G-CS and is addressed to the terminal A. Is called (arrow Y8, calling process).

When the MSC 50 of the 3G-CS network 200 receives a call addressed to the terminal A from the terminal B, the MSC 50 issues an IAM signal to the MGCS 30 (arrow Y9). The MGCF 40 receiving this sends an INVITE message to the CSCF 20 (arrow Y10). When CSCF 20 receives this INVITE message, terminal B performs IMS based on the location registration information.
It authenticates that it is a legitimate IMS terminal registered in SIP, and considers it as a CS call from IMS terminal B, and sends an INVITE message to terminal A (arrow Y11).

  Upon receiving this INVETE message, the session continuation control unit 111 of the intra-company SIP server 11 uses the calling identifier (telephone number or NAI etc.) and called party identifier (phone number or NAI etc.) information in the INVITE message. The call message is recognized as being addressed from the terminal B to the terminal A, the state information of the session management target terminal B is referred to, the terminal B recognizes that the terminal A is in an extension-extension call, and the call message is It is determined that terminal B is handed over from the WLAN to the 3GCS side. Based on this determination, session continuation control unit 111 sends a REINVITE message to terminal A in order to continue the session between terminals A and B (arrow Y12). Thereafter, the 200OK message of terminal A is returned to the CSCF 20 via the in-house SIP server 11 (arrow Y13). With the above C-plane processing, the CSCF 20 recognizes that the CS call of the IMS terminal B has started, while the enterprise SIP server side determines that the voice session between the terminal B and the terminal A is continued.

  Then, subsequent voice path (RTP path) continuation processing is performed as follows. When terminal B uses a 3GCS line, when viewed from the terminal A side, the IP address / port # of terminal B corresponds to the IP address / Port # on the MGW 40 side. Therefore, the MGCF 30 declares the IP address of the MGW 40 to the counterpart terminal A via the CSCF 20. The terminal A that has received the REINVETE message including the IP address / Port # information from the CSCF 20 switches the RTP packet (arrow Y6) sent to the terminal B to the MGW 40 side (arrow Y14 in FIG. 6). Specifically, the destination of the RTP packet of terminal A is switched from the IP address / PORT # of terminal B to the IP address / Port # of MGW 40. As a result, the voice session between the terminals A and B is continued (session switching step). Note that after the session is switched, the state information indicating the communication states of the terminals A and B is updated as shown in FIG.

  Next, as described above, while the user of terminal B is out, he / she goes back to the company while making a 3GCS line-extension call with the terminal A user (arrow Y21), and the extension-extension call is performed using terminal A and the corporate LAN. An example of an operation (communication continuation process) for continuing the call after shifting to is described with reference to FIG.

  First, when the terminal B is handed over from 3GCS to the wireless LAN (wireless LAN connection process), the terminal B sends an INVITE message to the company-side SIP server 11 (arrow Y22). Upon receiving this INVITE message, the company-side SIP server 11 makes a call using the 3GCS line with the terminal A until just before this INVITE message, based on the INVITE message information and the state information of the session continuation control unit 111 in the company SIP server. It is determined as a call session continuation request from terminal B that has been waiting. Based on this determination, the company-side SIP server 11 changes the call state between the terminals A and B from the call using the extension-3GCS line to the extension-extension call. Specifically, the following session continuation processing is performed.

  The company-side SIP server 11 issues a REINVITE message to the terminal A (arrow Y23). When the terminal A returns a 200OK message to the company-side SIP server 11 (arrow Y24), the company-side SIP server 11 returns 200OK to the terminal B (arrow 25). Further, instead of the terminal B, a BYE message is sent to the CSCF 20 (arrow Y26). As a result, in the CSCF 20, the IMS terminal B determines that the call using the 3GCS line has ended, and instructs the MGCF 30 to release the terminal B's 3GCS line (Release) (arrow Y27).

  Then, a voice path (RTP path) continuation process is performed. Specifically, when the terminal A receives the 200OK message from the enterprise-side SIP server, the terminal A switches the RTP packet sent to the MGW to the terminal B according to the information in the message. As a result, the voice session between the terminals A and B is continued in the corporate LAN (arrow Y28, session switching step). Then, after the session is switched, the state information indicating the communication state of the terminals A and B is updated.

  Further, in this embodiment, as shown in FIG. 8, the present invention can also be applied when a public wireless LAN 80 is used. In the example of this figure, VCC APPLICATION25, 3G operator public wireless LAN 80 is added to the configuration shown in FIG. The VCC APPLICATION 25 is the same as that of the conventional example described above.

  In this example, the user of the terminal B enters the area of the public WLAN 80 of the 3G operator (arrow Y31) while talking to the terminal A in the company using the 3GCS line on the go, and the public WLAN 80 from the call using the 3GCS line It relates to the case of transitioning to a call using. Terminal B sends an INVITE message to CSCF 20 in order to continue a call with terminal A using public WLAN 80 (arrow Y32). Then, the VCC APPLICATION 125 that receives the INVITE message via the CSCF determines that this message is a voice session continuation request from the terminal B, and provides a voice session continuation service between the terminal B and the terminal A by a known VCC means. Then, a REINVITE message is sent to terminal A (arrow Y33). Thereby, a session is established between the terminal A in the corporate LAN network 400 and the terminal B in the public WLAN network 80 (arrow Y34).

  As described above, according to the present embodiment, first, when the terminal B user and the terminal A user make an extension-extension call, the IMS side does not regard this call as an IMS call, but assumes that the IMS SIP registration has been made. Hesitate. Then, when the terminal B user goes out while making an extension-extension call with the terminal A user and shifts to a call using a 3GCS line outside the corporate WLAN area, the corporate SIP server 11 is connected to the terminal B and the terminal Provide A's voice session continuation service. The IMS recognizes that the IMS call has started. Conversely, when the terminal B user goes out and goes back to the company while making a 3GCS line-extension call with the terminal A user and moves to the extension-extension call using the terminal A and WLAN, Provide a voice session continuation service for terminal B and terminal A. At this time, the IMS side recognizes that the IMS call has ended. Furthermore, when the terminal B user goes to the 3G operator's public WLAN 80 area while making a call to the company's terminal A using the 3GCS line on the go, the call using the 3GCS line is changed to the call using the public WLAN 80. Alternatively, when the terminal B user moves out of the public WLAN area and shifts to a call using a 3GCS line, the voice session continuation service of the terminal B and the terminal A is supported by a known VCC on the IMS side.

  Therefore, in the above embodiment, a means for providing a voice session continuation service according to a call state between WLAN / 3G dual terminal users, that is, a case in which the session anchor function is provided by the company-side SIP server 11 and a VCC APPLICATION25 which is a known means on the IMS side. It is possible to provide a hierarchical voice session continuation service divided into cases provided by

  As a result, in the case of the prior art for the operator, the operator network side must handle the enterprise extension call or the IPS side VoIP call which is not originally handled. However, according to the present invention, it has hierarchical voice session continuation means. Therefore, there is no need to handle internal company calls or VoIP calls within the ISP network. In addition, it is not necessary for a company to newly introduce a secure VPN network because extension calls are not outside the corporate network. Same effect for ISP.

  In the above embodiment, the case of the voice session continuation system between the corporate VoIP communication system and the mobile network has been described as an example. However, the present invention is limited to the voice session continuation system between the voice extension system of the corporate network and the mobile network. It can also be applied to a voice session continuation system between a mobile network and a VoIP network operated by an ISP.

  Next, a second embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 9, in this embodiment, in the corporate LAN network 400, in addition to the corporate session controller 11 that controls extension calls as described above, the NAT 12 (address translation device) that performs address translation of the RTP path. Is equipped. The means 10 combining the in-company session controller 11 and the NAT 12 may be configured by a session border controller (SBC).

  With the above configuration, for example, when the terminal B performs handover from the in-house wireless LAN to 3GCS and continues the voice session with the terminal A, the voice interruption time at the time of handover is shortened. Specifically, in a corporate VoIP system, when the other party is an external line, NAT 12 is usually present on the corporate side in the voice packet route, and the private IP address space in the corporate and the global IP address space for the external line are converted. . At this time, the RTP path is MGW 40 (for terminal B) −enterprise side NAT 12−terminal A (see FIG. 10). In this embodiment, the NAT process is used to conceal that the terminal A has HOed from the wireless LAN to 3GCS by using the NAT process, and the voice interruption time associated with the handover is shortened. Here, with reference to FIG. 10 and FIG. 11, the operation | movement description in the case of aiming at shortening of the audio | voice interruption time accompanying a handover is performed.

  First, FIG. 10 shows an operation example for shortening the voice interruption time of the call with the terminal A when the terminal B is handed over from the wireless LAN to 3GCS. When the enterprise-side SIP server 11 receives an INVITE associated with the call from terminal B via 3GCS from the CSCF 20 (arrow Y41) and recognizes the INVITE message addressed to terminal A from the terminal B, the enterprise-side SIP server 11 sends a terminal to the CSCF 20 The IP address / PORT # (IP (NAT) / port (NAT)) information of NAT12 corresponding to the IP address / PORT # (IP (A) / port (A)) of A is returned as a 200 OK message (arrow Y42). ).

In parallel with this, the enterprise-side SIP server 11 performs setting control for the following RTP header conversion processing so that the terminal A does not have to be aware of the handover of the terminal B with respect to the NAT 12 (arrow Y43, address conversion). Setting process). That is, as shown in FIG. 10, for an RTP header addressed from terminal B to terminal A, Source; IP (MGW) / Port (MGW), Destination; IP (NAT) / Port (NAT) is set to Source; IP (B ) / Port (B)
Destination; converted to IP (A) / Port (A), while for the RTP header addressed from terminal A to terminal B, Source;
IP (A) / Port (A), Destination; Convert IP (B) / Port (B) to Source; IP (NAT) / Port (NAT), Destination; IP (MGW) / Port (MGW) Between Y46 and Y45). When the MGCF 30 receives a 200 OK message from the company-side SIP server 11 (arrow Y42), the NAT 12 IP address / Port # ( A command for setting IP (NAT) / port (NAT)) is issued (arrow Y44). With the above settings, the RTP path between terminal B and terminal A is established, and the voice call is resumed. Terminal A does not need to recognize that terminal B has been handed over from the wireless LAN to the 3GCS side, and as a result, RTP path switching of terminal A can be omitted. Become.

  FIG. 11 shows an example of an operation for shortening the voice interruption time when the terminal B returns to the company while making a 3GCS line-extension call with the terminal A and shifts to the extension-extension call with the terminal A. First, in the session continuation process, when the company-side SIP server 11 receives an INVITE message from terminal B via wireless LAN access (arrow Y51), it returns a 200OK message on behalf of terminal A (arrow Y52). As a result, the terminal A is not made aware of the handover of the terminal B from the 3GCS to the WLAN. In parallel with this, the RTP header conversion setting in the RTP path between the MGW 40 and the terminal A set as shown in FIG. That is, the address setting is performed so that the partner terminal becomes the data transmission destination / transmission source. Further, a BYE message is issued to the CSCF 20 (arrow Y53), and the 3GCS line of terminal B is disconnected.

  Then, in the voice path (RTP path) continuation process, the intra-company SIP server 11 conceals that the terminal B has been handed over from 3GCS to the wireless LAN in order to shorten the voice interruption time. Specifically, the following processing is performed. Terminal B is handed over from 3GCS to the wireless LAN, and INVITE including the IP address PORT # (IP (B) / Port (B)) used by the terminal itself is sent to the enterprise-side SIP server 11 (arrow Y51). When the company-side SIP server 11 receives the INVITE message from terminal B, it returns 200 OK including the IP address / PORT # (IP (A) / Port (A)) information of terminal A on behalf of terminal A (arrow Y52). . As a result, the terminal B and the terminal A start an extension-extension call. Here, the NAT 12 is positioned as a default router between the terminal A and the terminal B, and the RTP packets of the terminal A and the terminal B are once terminated at the NAT 12 (arrow Y54). As a result, it is possible to provide a means for the NAT 12 to buffer RTP packets that should be lost at the time of handover from the 3GCS of the terminal B to the WLAN, and to continue the lossless voice continuation service at the time of handover. As described above, since the terminal A does not recognize that the terminal B has been handed over from the 3GCS to the wireless LAN, the terminal A does not need to perform the RTP packet switching process, and the voice interruption time during the handover can be shortened.

  Next, a third embodiment of the present invention will be described with reference to FIG. As shown in this figure, in this embodiment, in addition to the configuration including the VCC APPLICATION 125 shown in FIG. 8 of the first embodiment, the NAT 12 (session border controller 10) of the second embodiment is provided. On the side, a session border controller 90 having a C plane control unit 91 and a U plane control unit 92 is provided.

  In this embodiment, the terminal B user enters the public WLAN 80 area of the 3G operator while talking to the terminal A in the company using the 3GCS line on the go, and the call using the public WLAN 80 from the call using the 3GCS line. Regarding the transition to. Terminal B sends an INVITE message to CSCF 20 in order to continue a call with terminal A using public WLAN 80. The CSCF 20 that has received the INVITE message provides a voice session continuation service between the terminal B and the terminal A by a known VCC means in cooperation with the VCC APPLICATION 125. Here, the session border controller 90 deployed in the mobile operator network conceals that the terminal B has been handed over from the 3GCS to the public WLAN 80 to the enterprise-side SIP server 11. The concealing means is basically the same as the operation of the company-side session border controller 10 described in the operation in the second embodiment. When the C-plane control unit 91 of the session border controller 90 receives the REINVITE message from the CSCF 20, it changes to a company-side session border controller and returns 200OK to the CSCF. Further, the U plane control unit 92 terminates the RTP packet with the MGW and performs the RTP path switching process of the enterprise NAT 12. As a result, the voice interruption time associated with the HO from the 3GCS of the terminal B to the public WLAN 80 can be reduced.

  INDUSTRIAL APPLICABILITY The present invention can provide a dual terminal use service to a user when used by a company or ISP that provides a wireless LAN network, and has industrial applicability.

1 is a schematic diagram illustrating an overall configuration of a system in Embodiment 1. FIG. It is a functional block diagram which shows the structure of the in-company session controller disclosed in FIG. FIG. 3 is a diagram illustrating an example of state information stored in a session state information storage unit disclosed in FIG. 2. It is explanatory drawing which shows the communication operation | movement in the system disclosed in FIG. It is explanatory drawing which shows the communication operation | movement in the system disclosed in FIG. It is explanatory drawing which shows the communication operation | movement in the system disclosed in FIG. It is explanatory drawing which shows the communication operation | movement in the system disclosed in FIG. It is explanatory drawing which shows the structure and communication operation | movement of the modification of the system disclosed in FIG. It is the schematic which shows the whole structure of the system in Example 2. FIG. It is explanatory drawing which shows the communication operation | movement in the system disclosed in FIG. It is explanatory drawing which shows the communication operation | movement in the system disclosed in FIG. FIG. 10 is a schematic diagram illustrating an overall configuration of a system according to a third embodiment. It is the schematic which shows the whole structure of the system in a prior art example. It is explanatory drawing which shows the communication operation | movement in the prior art system disclosed in FIG. It is explanatory drawing which shows the mode of the handover of a dual terminal.

Explanation of symbols

11 In-house session controller 20 CSCF
30 MGCF
40 MGW
50 MSC
60 base station 70 RNC
80 Public WLAN network 100 Mobile network 110 Extension session controller 111 Session continuation control unit 200 3GCS
300 IMS
400 wireless LAN network

Claims (14)

A wireless LAN control device for controlling connection in the wireless LAN network of a portable communication terminal connectable to the wireless LAN network and the mobile phone network, and installed in the mobile phone network and the Internet network connected to the wireless LAN network A connection control device for controlling connection of the portable communication terminal, and a communication continuation method for continuing communication between different networks of the portable communication terminal,
The wireless LAN control device performs location registration of the portable communication terminal connected to the wireless LAN network with respect to itself and the connection control device on the Internet network, and stores location registration information in each device. A location registration process;
A state information management step in which the wireless LAN control device detects a communication state of the portable communication terminal and stores and manages it as state information;
When one portable communication terminal among the portable communication terminals in communication connection with each other moves in and out of the wireless LAN network, the connection control device and the wireless LAN control device A communication continuation step for controlling to continue communication between the portable communication terminals based on the state information;
A communication continuation method characterized by comprising: The state information includes connection destination terminal information of the portable communication terminal in communication connection, and network information to which the portable communication terminal is connected.
The communication continuation method according to claim 1. When two portable communication terminals are in communication connection in the wireless LAN network,
In the communication continuation step, when the one portable communication terminal exits from the wireless LAN network to the cellular phone network, the one portable communication terminal moves from the cellular phone network to the connection control device and the wireless LAN control. A calling step of calling the other portable communication terminal via the device, and the connection control device that has received a call from the one portable communication terminal calls the wireless LAN control device And a session switching step for switching the session so that the wireless LAN control device receiving the communication connection between the one portable communication terminal and the other portable communication terminal is continued.
The communication continuation method according to claim 2. In the session switching step, the wireless LAN control device determines the connection destination of the established session of the other portable communication terminal connected to the wireless LAN network as the one mobile phone in the wireless LAN network. Switching from a portable communication terminal to the one portable communication terminal connected to the mobile phone network via the connection control device;
The communication continuation method according to claim 3. When one portable communication terminal connected to the cellular phone network and the other portable communication terminal connected to the wireless LAN network are in communication connection,
The communication continuation step includes a wireless LAN connection step for connecting the one portable communication terminal to the wireless LAN network when the one portable communication terminal enters the wireless LAN network from the cellular phone network; The wireless LAN control device that has received this connection has a session switching step of switching a session so that the communication connection between the one and the other portable communication terminals is continued.
5. The communication continuation method according to claim 2, 3 or 4. In the session switching step, the wireless LAN control device transmits a connection destination of an established session of the other portable communication terminal connected to the wireless LAN network via the connection control device. from the one of the mobile communication terminals connected to the network, it switches to said one mobile communication terminal connected to a wireless LAN network,
The communication continuation method according to claim 5. In the session switching step, the destination / source of data in the established session of the other portable communication terminal connected to the wireless LAN network is always the one portable communication before and after the session switching. An address conversion setting step for performing address conversion setting for an address conversion device through which data communicated between the one and the other portable communication terminals passes to be a terminal;
7. The communication continuation method according to claim 3, 4, 5, or 6. A wireless LAN control device for controlling connection in the wireless LAN network of a portable communication terminal connectable to the wireless LAN network and the mobile phone network, and installed in the mobile phone network and the Internet network connected to the wireless LAN network A connection control device for controlling connection of the portable communication terminal, and a communication continuation system for continuing communication between different networks of the portable communication terminal,
Location where the wireless LAN control device registers the location of the portable communication terminal connected to the wireless LAN network with respect to its own device and the connection control device on the Internet network and stores location registration information in each device Registration means; and state information management means for detecting and managing the communication state of the portable communication terminal as state information,
When one of the portable communication terminals in communication connection between the connection control device and the wireless LAN control device moves in and out of the wireless LAN network, the location registration information and Communication continuation means for controlling to continue communication between the portable communication terminals based on the state information;
A communication continuation system characterized by comprising: A wireless LAN control device for performing connection control in a wireless LAN network of a portable communication terminal connectable to a wireless LAN network and a mobile phone network,
Location control of the portable communication terminal connected to the wireless LAN network is connected to the mobile device and the mobile communication terminal installed in the Internet network connected to the mobile phone network and the wireless LAN network. A location registration means for storing location registration information in each device,
State information management means for detecting the communication state of the portable communication terminal and storing and managing it as state information;
The communication between the portable communication terminals is continued based on the state information when one of the portable communication terminals in communication connection with each other moves in and out of the wireless LAN network. A communication continuation means to control;
A wireless LAN control device comprising: When two portable communication terminals are in communication connection in the wireless LAN network,
The communication continuation means is configured such that when the one portable communication terminal exits from the wireless LAN network to the cellular phone network, the one portable communication terminal transmits the connection control device and the wireless LAN control from the cellular phone network. A call is made to the other portable communication terminal via the device, and the connection control device that has received the call accepts a call made to the wireless LAN control device, and the wireless LAN control device And a session switching means for switching the session so that the communication connection between the other portable communication terminal is continued,
The wireless LAN control device according to claim 9. The session switching means sends a connection destination of an established session of the other portable communication terminal connected to the wireless LAN network from the one portable communication terminal in the wireless LAN network to the connection Switching to the one portable communication terminal connected to the cellular phone network via a control device;
The wireless LAN control device according to claim 10. When one portable communication terminal connected to the cellular phone network and the other portable communication terminal connected to the wireless LAN network are in communication connection,
When the one portable communication terminal enters the wireless LAN network from the cellular phone network, the one communication communication unit connects to the wireless LAN network and receives this connection. The wireless LAN control device includes session switching means for switching a session so that communication connection between the one and the other portable communication terminals is continued.
The wireless LAN control device according to claim 9, 10 or 11. The session switching means, the connection of the session the being established in the other mobile communication terminal connected to a wireless LAN network, the one connected to the mobile phone network through the connection control device from the mobile communication terminal switches to the said one of the mobile communication terminal connected to a wireless LAN network,
The wireless LAN control device according to claim 12. A wireless LAN control device that performs connection control in the wireless LAN network of a portable communication terminal that can be connected to a wireless LAN network and a mobile phone network.
Location control of the portable communication terminal connected to the wireless LAN network is connected to the mobile device and the mobile communication terminal installed in the Internet network connected to the mobile phone network and the wireless LAN network. A position registration means for performing connection to the connection control device, and storing location registration information in each device;
State information management means for detecting the communication state of the portable communication terminal and storing and managing it as state information;
The communication between the portable communication terminals is continued based on the state information when one of the portable communication terminals in communication connection with each other moves in and out of the wireless LAN network. A communication continuation means to control;
A program to realize

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