JP4477884B2 - Network control device, communication terminal, communication connection method, connection registration method to network - Google Patents

Description

  The present invention relates to a network control device that controls connection to communication terminals that can be connected to a plurality of networks having different communication methods.

  Various protocols have been proposed for establishing, changing, and terminating multimedia sessions over IP networks. One of these protocols is SIP (Session Initiation Protocol).

  SIP is an application layer signaling protocol. It has been proposed by the working group of IETF (Internet Engineering Task Force) and is currently standardized by RFC3261. Services that can be implemented by SIP include various services such as video conferencing, telephone calls, instant messaging, and presence. In 3GPP (The Third Generation Project), it is determined that SIP is used to establish a session on the network side of a next-generation mobile communication system.

  In a communication system based on standard SIP, a communication terminal serving as a session originator transmits a session start message, and the message is received by the SIP proxy. Then, the SIP proxy routes the session start message to the receiving communication terminal based on the destination described in the standard field of the header of the received session start message.

  Patent Document 1 discloses a communication system that can select a communication terminal as a communication destination based on the intention of a user of a caller. This communication system is a communication system constructed using SIP, and has a calling end point, a called end point, and a server. In this communication system, a location server and a database are connected to a server. The location server has location information used for routing calls between the calling endpoint and the called endpoint. The database includes information on attributes of communication terminals included in the called network.

  In this communication system, the calling end point has information on the called end point in advance. When communication is started using this communication system, the calling endpoint creates and transmits a call start message in which main body routing information is added to standard routing information called header routing information. The main body routing information includes information related to the intention of the user (calling party) who owns the calling communication terminal. For example, when the user of the calling communication terminal wants to talk to a salesperson who is familiar with the washing machine, a keyword representing the attribute of the called terminal called “washing machine” is described in the main body routing information.

  When the server receives the call start message transmitted from the calling end point, the server determines a destination address based on the routing information included in the call start message. More specifically, the server estimates the caller's intention based on the keyword included in the main body routing information, and acquires the address to be routed from the database. Then, the server transmits a call start message to the acquired address.

As a result, in the communication system described in Patent Document 1, it is possible to route the call start message to a terminal based on the intention of the caller. For example, when the standard routing information is a general electric company address and the routing information associated with the caller is “washing machine”, the washing machine of the electric company is based on the location server and database. It is possible to connect the call to an expert salesperson's terminal that can answer questions about.
JP 2002-335267 A (pages 5 and 6, FIG. 2)

  In recent years, the types of communication networks have increased, and the number of communication terminals connected to the communication networks has increased. Along with this, communication terminals capable of supporting networks with different communication methods using a single communication terminal have been developed. A user who makes a call from such a communication terminal can select a network to be used according to the contents of communication or according to the state of the network to which the communication terminal is connected. In the future, even when such a user receives an incoming call, it is desired to select a network to be used in consideration of a radio wave condition, a communication partner, and the like.

  However, in the communication system described in Patent Document 1, routing is performed based on the intention of the user on the calling side, but the request on the called side is not considered. In addition, although the radio wave reception status of the receiving terminal changes constantly, the above communication system does not consider the status of the receiving terminal. Japanese Patent Laid-Open No. 8-340308 describes a communication method for selecting a data transfer rate using the radio wave intensity detected by a communication terminal. However, this communication method also does not take into account the radio field intensity of the incoming communication terminal. That is, in the conventional communication system, when there are a plurality of network candidates that can be received at the receiving communication terminal, the reception status of the receiving communication terminal, for example, the radio wave intensity is not considered. There was a possibility of receiving incoming calls via a network with poor reception.

  In view of the above-described background, an object of the present invention is to provide a network control device that can select a network to start connection in consideration of a user request of a receiving terminal or a radio wave condition of the receiving terminal.

  The network control device of the present invention is a network control device that controls connection to a communication terminal connectable to a plurality of networks having different communication methods, and the communication control device selects one of the plurality of networks. A network selection information storage means for storing information registered from a terminal; a connection request receiving means for receiving a connection request for communication addressed to the communication terminal; and a connection established by a connection request received by the connection request receiving means. Network selection means for selecting a network for communication to be performed based on information stored in the network selection information storage means, and the connection request is transmitted to the communication terminal through the network selected by the network selection means. Connection request transmission means.

  With this configuration, since the network for communication performed by the connection established by the connection request is selected on the basis of the network selection information registered from the communication terminal on the called side, the called user of the called side can be selected as the called side network. It becomes possible to select what suits the request. Further, the user of the communication terminal can set the network to be used for incoming calls based on, for example, the communication partner and communication type, the radio wave reception status of the communication terminal, the communication speed of the network, security, and the like.

  The network selection information storage means stores information on the strength of radio waves received by the communication terminal through each of a plurality of networks, and the network selection means stores the strength of radio waves stored in the network selection information storage means. The network may be selected based on the information regarding.

  With this configuration, it is possible to select a network that is highly likely to communicate with the communication terminal based on the radio wave intensity. Thereby, it is possible to reduce the number of times the connection request is retransmitted to reduce network congestion, and to reduce the possibility that the communication connection is disconnected even after the communication connection.

  The network selection information storage means stores information on the radio wave intensity required for communication for each communication type, and the network selection means is performed by a connection established by a connection request received by the connection request reception means. The communication type may be determined, and the network may be selected based on the radio wave intensity required for the determined type of communication and the information regarding the radio wave intensity of the communication terminal.

  With this configuration, it is possible to select a network having a radio wave intensity necessary for communication performed by a connection established by a connection request, so that communication after connection can be performed smoothly. The communication type is information relating to communication contents such as multimedia communication and voice communication.

  The network selection information storage means stores information related to network security necessary for communication, and the network selection means selects a network based on the security information stored in the network selection information storage means. Also good.

  With this configuration, it is possible to select a network on the receiving side having communication security desired by the user of the communication terminal on the receiving side.

  Further, the network selection information storage means stores the security-related information in association with information related to a connection request transmission source terminal, and the network selection means receives the transmission request from the connection request received by the connection request reception means. Information relating to a terminal may be extracted, information relating to security necessary for communication with the transmission source terminal may be extracted from the network selection information storage unit, and a network may be selected based on the extracted information relating to security.

  With this configuration, it is possible to select a receiving-side network having communication security that the user of the receiving-side communication terminal desires to secure according to the communication partner.

  The network selection information storage means stores information related to the security for each communication type, and the network selection means determines a communication type to be performed in a connection established by a connection request received by the connection request reception means. Then, information related to security necessary for communication of the communication type may be extracted from the network selection information storage unit, and a network may be selected based on the extracted information related to security.

  With this configuration, it is possible to select a network on the receiving side having communication security desired by the user of the communication terminal on the receiving side according to the communication type.

  The network selection information storage means stores information related to the communication speed of the network necessary for communication, and the network selection means selects a network based on the information related to the communication speed stored in the network selection information storage means. May be.

  With this configuration, it is possible to select a network on the receiving side having a communication speed for communication that the user of the communication terminal on the receiving side desires to secure.

  The network selection information storage means stores information relating to the communication speed in association with information relating to a connection request transmission source terminal, and the network selection means transmits a transmission source from the connection request received by the connection request reception means. Information relating to the terminal of the transmission source, information relating to the communication speed necessary for communication with the terminal of the transmission source is extracted from the network selection information storage means, and a network may be selected based on the information relating to the extracted communication speed. Good.

  With this configuration, it is possible to select a network on the receiving side having a communication speed of communication that the user of the communication terminal on the receiving side desires to secure according to the communication partner.

  In addition, the network selection information storage unit stores information on the communication speed for each communication type, and the network selection unit determines a communication type performed in a connection established by a connection request received by the connection request reception unit. The information regarding the communication speed necessary for the communication of the communication type may be extracted from the network selection information storage unit, and the network may be selected based on the extracted information regarding the communication speed.

  With this configuration, it is possible to select a network having a communication speed necessary for communication performed by a connection established by a connection request, so that communication after connection can be performed smoothly. The communication type is information relating to communication contents such as multimedia communication and voice communication.

  A network control apparatus according to another aspect of the present invention is a network control apparatus that controls connection to a communication terminal connectable to a plurality of networks having different communication methods, and is received by the communication terminal through the plurality of networks. Based on the radio field intensity information received from the communication terminal and the radio field intensity information received by the radio field intensity information receiving unit, the communication terminal is connected to the one network. Registration processing means for registering as a terminal or canceling the registration; and connection request transmitting means for transmitting a connection request addressed to the communication terminal through a network selected from the networks registered by the registration processing means. Prepare.

  With this configuration, the network control device can manage the radio wave intensity information that can be detected only by the communication terminal. Further, since it is determined whether or not to register as a terminal connected to the network based on the radio wave intensity information, it is possible to register an appropriate network as a candidate for the network used for communication.

  The registration processing unit registers the communication terminal when the radio field intensity of the communication terminal exceeds a predetermined threshold based on the radio field intensity information received by the radio field intensity information receiving unit, and the communication terminal The registration of the communication terminal may be canceled when the radio field intensity is less than or equal to the threshold value.

  With this configuration, a network having a high radio wave intensity is registered, and the network registered as a candidate has a high possibility of communication connection. Therefore, it is possible to reduce the number of retransmissions of the connection request to alleviate network congestion, and to reduce the possibility that the communication connection is disconnected even after the communication connection.

  The radio wave intensity information receiving unit may receive a SIP message including the radio wave intensity information, and the registration processing unit may extract the radio wave intensity information from the body of the SIP message received by the radio wave intensity information receiving unit. .

  In SIP, since additional information can be described in a message body, it is preferable to transmit information on radio wave intensity using a SIP message.

  The communication terminal of the present invention is a communication terminal connected to a network control device that selects a network to be used for incoming calls from a plurality of networks having different communication methods based on radio wave intensity in the communication terminal, Radio wave intensity detection means for detecting the intensity of radio waves received through a plurality of networks with different communication methods, and when the radio wave intensity detected by the radio wave intensity detection means changes beyond a predetermined threshold, Radio wave intensity information transmitting means for transmitting information on the intensity.

  With this configuration, when the change in the radio field intensity is small, the radio field intensity information is not transmitted. Therefore, the number of transmissions of the radio field intensity information is limited, thereby reducing network congestion. Further, since the radio field strength information is transmitted to the network control device when the change in the radio field strength is large, it is possible to notify the network control device of the radio field strength information useful for network selection.

  A communication terminal according to another aspect of the present invention is based on radio wave intensity detection means for detecting the intensity of radio waves received through a plurality of networks having different communication methods, and the radio wave intensity detected by the radio wave intensity detection means, A determination unit that determines whether or not to use the one network, and for registering the communication terminal as a terminal connected to the network or canceling the registration based on a determination result by the determination unit Request message transmitting means for transmitting a request message to a network control device that controls connection to the network.

  With this configuration, the connection is registered for the network determined to be used according to the radio wave intensity, so that the incoming call can be received through an appropriate network.

  The determination means determines that the one network is to be used when the radio wave intensity detected by the radio wave intensity detection means exceeds a predetermined threshold, and the radio wave intensity detected by the radio wave intensity detection means You may determine not to use the said one network when it is below the said threshold value.

  With this configuration, a network having a radio field intensity exceeding a threshold value is registered, and the network registered as a candidate has a high possibility of being able to communicate. Therefore, it is possible to reduce the number of retransmissions of the connection request to alleviate network congestion, and to reduce the possibility that the communication connection is disconnected even after the communication connection.

  Further, the request message transmission unit may transmit the request message when a determination result of whether or not the one network is used by the determination unit changes.

  With this configuration, since the request message is transmitted only when the determination result of whether the network is used or not used, the number of times of transmitting the request message can be reduced.

  Further, the request message transmitting means may transmit a SIP message including information on whether to register the communication terminal in the network or cancel the registration.

  As a message for registering as a terminal connected to the network, it is preferable to use a SIP register message. The connection registration can be canceled by setting the connection duration time to 0 in the header of the register message.

  The communication connection method of the present invention is a communication connection method to a communication terminal connectable to a plurality of networks having different communication methods, and a network control device that controls the communication terminal receives a connection request for communication addressed to the communication terminal A connection request receiving step of receiving the communication request, and the network control device registers a plurality of networks registered from the communication terminal for communication performed by the connection established by the connection request received in the connection request receiving step. A network selection step of selecting based on information for selecting one of the networks, and a connection in which the network control device transmits the connection request to the communication terminal through the network selected in the network selection step A request transmission step.

  With this configuration, since the network for communication performed by the connection established by the connection request is selected on the basis of the network selection information registered from the communication terminal on the called side, the called user of the called side can be selected as the called side network. It becomes possible to select what suits the request. Further, the user of the communication terminal can set the network to be used for incoming calls based on, for example, the communication partner and communication type, the radio wave reception status of the communication terminal, the communication speed of the network, security, and the like. Various configurations of the network control device of the present invention described above can be applied to the communication connection method of the present invention.

  The network connection registration method of the present invention is a method of registering a communication terminal connectable to a plurality of networks having different communication methods as a terminal connected to the network, and the network control device for controlling the communication terminal includes: Based on the radio field intensity information received in the radio field intensity information receiving step, the radio field intensity information received from the communication terminal, the radio field intensity information related to the radio field intensity received by the communication terminal through the plurality of networks, A registration processing step for registering the communication terminal as a terminal connected to the one network or canceling the registration, and the network registered in the registration processing step transmits a connection request addressed to the communication terminal. Candidate for the network to use.

  With this configuration, the network control device can manage the radio wave intensity information that can be detected only by the communication terminal. Further, since it is determined whether or not to register as a terminal connected to the network based on the radio wave intensity information, it is possible to register an appropriate network as a candidate for the network used for communication. Note that the various configurations of the network control device of the present invention described above can also be applied to the network connection registration method of the present invention.

  The network connection registration method of the present invention is based on a radio wave intensity detection step for detecting the intensity of radio waves received by a communication terminal through a plurality of networks having different communication methods, and the radio wave intensity detected in the radio wave intensity detection step. Determining whether the communication terminal uses the one network, and registering the communication terminal as a terminal connected to the network based on a determination result in the determination step, or A request message transmission step of transmitting a request message for canceling registration to a network control device that controls connection to the network.

  With this configuration, the connection is registered for the network determined to be used according to the radio wave intensity, so that the incoming call can be received through an appropriate network. Note that the various configurations of the communication terminal of the present invention described above can also be applied to the network connection registration method of the present invention.

  Since the present invention selects a network for communication performed by a connection established by a connection request based on network selection information registered from a communication terminal on the called side, in an area where a plurality of different networks overlap. Thus, it is possible to select a network that meets the needs of the receiving user as the receiving network.

  Hereinafter, a network control device and a communication terminal according to an embodiment of the present invention will be described.

  FIG. 1 is a diagram illustrating a configuration of a network control device 10 according to the first embodiment. Before describing the configuration of the network control device 10 according to the first embodiment, an environment to which the network control device 10 and the communication terminal 40 according to the embodiment are applied will be described.

  FIG. 2 is a diagram illustrating an environment to which the network control device 10 and the communication terminal 40 according to the embodiment of this invention are applied. FIG. 2 shows a system in which a communication terminal 40 connectable to two networks and a communication terminal 70 connected to an ISP (Internet Service Provider) communicate.

  The communication terminal 40 is a terminal that can be connected to a plurality of different communication networks. Here, the communication terminal 40 can be connected to a 3G network and a WLAN network. The communication terminal 40 is managed by one number. That is, the communication terminal 40 can be accessed with the same number when performing communication using any network. The communication terminal 40 is an IP compatible terminal. The communication terminal 40 is, for example, a mobile phone terminal, an IP phone terminal, a PDA having a function of connecting to a wireless network, a personal computer that can be connected to a network, or a network home appliance. The communication terminal 70 is connected to the ISP. Communication terminal 70 may be connected by another carrier other than ISP.

  As shown in FIG. 2, a center 60 for managing a plurality of networks is provided in the network environment of the present embodiment. The center 60 integrally manages authentication, billing, session management, QoS control, and the like in a plurality of networks. The network control device 10 of the present embodiment is installed in the center. The network control device 10 is a device that manages session establishment, disconnection, and network switching. In addition, the network control device 10 has a function of transmitting and receiving SIP messages.

  The network control apparatus 10 will be described with reference to FIG. The network control device 10 is a session management device for interworking between a 3G network and a WLAN network. The network control apparatus 10 has a SIP proxy, and establishes, disconnects, and routes a session by SIP.

  As illustrated in FIG. 1, the network control device 10 includes a message transfer unit 12, a message analysis unit 14, a routing control unit 24, and a terminal information storage unit 26. Although not shown, the network control device 10 also has the same configuration as the normal network control device 10 such as a storage unit that stores information (communication charges, bandwidth, etc.) related to the network.

  The message transfer unit 12 has a function of performing processing for creating a transmission message as a packet and processing for creating a reception packet as a message.

  The message analysis unit 14 has a function of analyzing a message transmitted and received by the message transfer unit 12. The message analysis unit 14 includes a message determination control unit 16 that controls the determination of the SIP message type and the operation associated therewith, and a register message analysis unit 18 that extracts the header and body of the register message and transmits them to the terminal information storage unit 26. , An invite message analysis unit 20 that extracts SDP (Session Description Protocol) information included in the body of the invite message and transmits the information to the routing control unit 24, and a message creation unit 22 that creates a transmission message. The register message is a SIP protocol message for registering that the terminal is connected to the network, and the invite message is a SIP protocol message for requesting the start of connection.

  The routing control unit 24 has a function of performing routing based on information stored in the terminal information storage unit 26. Since the terminal information storage unit 26 stores network selection conditions described below, routing can be performed using a network according to the request of the receiving terminal by performing routing based on this.

  The terminal information accumulating unit 26 accumulates information (radio wave intensity information) 28 relating to the radio wave intensity received by the communication terminal 40, information (selection condition information) 30 relating to a condition for selecting a network, and location information 32 of the communication terminal 40. It has the function to do. The location information 32 of the communication terminal 40 is information relating to the location where the communication terminal 40 exists, and is the same as the location information stored in a normal network control device. The radio wave intensity information 28 and the selection condition information 30 are network selection information registered from the communication terminal 40. Next, the radio wave intensity information 28 and the selection condition information 30 will be described.

  FIG. 3 is a diagram illustrating an example of the radio wave intensity information 28 stored in the terminal information storage unit 26. The radio wave intensity information 28 is information relating to the intensity with which the communication terminal 40 receives radio waves through each network. In the example shown in FIG. 3, the radio field intensity of the communication terminal A in the 3G network is Ea1, and the radio field intensity in the WLAN network is Ea2. The radio wave intensity information 28 is updated based on the radio wave intensity information transmitted from the communication terminal 40.

  FIG. 4A and FIG. 4B are diagrams illustrating an example of the selection condition information 30. FIG. 4A is a diagram showing an example of the selection condition 30a regarding the radio wave intensity, and FIG. 4B is a diagram showing an example of the selection condition 30b regarding the characteristics of the network.

  As shown in FIG. 4A, the selection condition 30a regarding the radio wave intensity is information on necessary radio wave intensity set for each communication medium. Necessary radio wave intensity information is set according to each network. For example, in the case of voice communication, the required radio field intensity in the 3G network is E1, and in the WLAN network is E2. Based on this condition, a network that satisfies the required radio field intensity is selected.

  As shown in FIG. 4B, the network condition selection condition 30b is set with information regarding the network characteristics to be selected in accordance with the receiving user URI, the calling user URI, and the communication media. For example, when the incoming user URI is U1, the outgoing user URI is S1, and the communication medium is voice, it is set to select a network with good sound quality. The selection condition 30b related to the characteristics of the network is set based on information from the communication terminal 40. In addition, this invention may also include the aspect which updates the selection condition information 30 by the notification from the user of the communication terminal 40. FIG. For example, the user may be able to input selection conditions via the Internet. Further, when the user purchases the communication terminal 40, it is also possible to register the contract contents at the time of purchase and the set network selection condition information 30. Alternatively, the selection condition can be notified when the communication terminal 40 is registered as a terminal connected to the network.

  Next, the communication terminal 40 according to the first embodiment will be described. FIG. 5 is a diagram illustrating a configuration of the communication terminal 40 according to the first embodiment. As shown in FIG. 5, the communication terminal 40 has a hierarchical configuration. The upper layer 42 corresponds to the application layer of the OSI reference model, and the lower layer 54 corresponds to the transport layer to the physical layer of the OSI reference model. In addition, the communication terminal 40 includes a radio wave intensity detection unit 64 that detects radio wave intensity between the upper layer 42 and the lower layer 54.

  The communication terminal 40 includes an application logic unit 44 and an application profile unit 46 that constitute a normal application, a radio wave intensity change boundary value storage unit 48, a connection control unit 50, and a user interface 52 in an upper layer 42. Further, the communication terminal 40 includes a communication protocol control unit 56, a radio interface control unit 58, a 3G interface 60, and a WLAN interface 62 in the lower layer 54. Hereinafter, each component of the communication terminal 40 will be described.

  The radio wave intensity change boundary value accumulation unit 48 accumulates information on the boundary value of the radio wave intensity change width used for determining whether or not to notify the network control apparatus 10 of radio wave intensity information.

  The connection control unit 50 has a function of determining whether or not to transmit information on the radio wave intensity to the network control device 10 and creating a register message based on the determination result. Whether or not to transmit the radio wave intensity information is determined by comparing the change width of the radio wave intensity detected by the radio wave intensity detector 64 with the boundary value of the radio wave intensity change.

  The communication protocol control unit 56 has a function of performing control related to the communication protocol in the wireless interface. The communication protocol control unit 56 corresponds to the transport layer and network layer of the OSI reference model.

  The wireless interface control unit 58 has a function of controlling a wireless interface necessary for performing wireless communication. The wireless interface control unit 58 corresponds to the data link layer of the OSI reference model.

  The 3G interface 60 is a wireless interface for accessing the 3G network, and the WLAN interface 62 is a wireless interface for accessing the WLAN network. The two interfaces 60 and 62 correspond to the physical layer of the OSI reference model.

  The radio wave intensity detector 64 has a function of detecting the radio wave intensity from the radio interfaces 60 and 62. The radio wave intensity detection unit 64 periodically detects the radio wave intensity and monitors changes in the radio wave intensity.

  Next, operations of the communication terminal 40 and the network control device 10 according to the present embodiment will be described.

  FIG. 6 is a diagram illustrating an operation in which the communication terminal 40 transmits radio wave intensity information. First, the communication terminal 40 detects information on the radio field intensity by using the radio field intensity detection unit 64 (S10), and inputs the detected information on the radio field intensity to the connection control unit 50. Further, the connection control unit 50 of the communication terminal 40 acquires information on the radio wave intensity change boundary value from the radio wave intensity change boundary value accumulation unit 48 (S12). Subsequently, the connection control unit 50 determines whether or not the change of the detected radio wave intensity with respect to the radio wave intensity at the previous detection exceeds the radio wave intensity change boundary value (S14).

  If the change width of the radio wave intensity exceeds the radio wave intensity change boundary value, the communication terminal 40 creates a message notifying the radio wave intensity information by the message creating unit 22 (S16). Here, a message in which information on the radio wave intensity is described in the SIP register message is created. Then, the communication terminal 40 transmits the created message to the network control device 10 (S18).

  Here, the sequence of the SIP register message will be described with reference to FIG. As shown in FIG. 7, the communication terminal 40 transmits a register message to the network control device 10, and the network control device 10 that has received this registers the communication terminal 40 of the transmission source and transmits a success response of 200 OK. This completes the register message sequence. By including the radio wave intensity information in the register message, it is possible to transmit the radio wave intensity information to the network control apparatus 10 without using a new message.

  If it is determined in step S14 that the detected change in the radio field intensity is equal to or less than the radio field intensity change boundary value, the communication terminal 40 acquires the radio field intensity information again without transmitting the radio field intensity information. The process proceeds to step S10. In this way, by transmitting the radio wave intensity information only when the change in the radio wave intensity exceeds a predetermined boundary value, the number of transmissions of the radio wave intensity information can be reduced, the processing load of the communication terminal 40 can be reduced, and the network congestion Can contribute to mitigation.

  FIG. 8 is a diagram showing a register message describing the radio field intensity information. The signal strength information is described in the body of the register message. In SIP, a body is a part that can describe information extended from standard information. The header of the register message includes items “From” and “To” describing the URI of the communication terminal 40 that is the transmission source, an item “Contact” describing the IP address of the registered wireless interface, and a period for requesting registration. And an item “Expires” in which information on the information is described. Here, no value is described in “Expires”. This means that registration is performed without setting a period.

  Next, the operation of the network control device 10 will be described. FIG. 9 is a diagram illustrating the operation of the network control device 10. The network control device 10 receives the message by the message transfer unit 12 (S20). The message transfer unit 12 transmits the received message to the message discrimination control unit 16. The network control device 10 determines the type of the received message by the message determination control unit 16 (S22). Depending on the determination result, the processing performed by the network control device 10 is divided into two. When the received message is a register message, the network control device 10 performs processing for accumulating information on the radio wave intensity at the communication terminal 40. When the received message is an invite message, the network control device 10 Processing to connect communication to the communication terminal 40 is performed.

  First, a case where the received message is a register message will be described. The network control device 10 inputs the received register message to the register message analysis unit 18. The register message analysis unit 18 extracts the header and body information of the register message (S24). Here, the URI of the communication terminal 40, the radio interface IP address supported by the terminal, and the radio wave intensity information are extracted. The register message analysis unit 18 identifies the communication terminal and the network from the extracted information, and stores the radio wave intensity information in the terminal information storage unit 26 (S26).

  Next, a case where the received message is an invite message will be described. The network control apparatus 10 inputs the received invite message to the invite message analysis unit 20. The invite message analysis unit 20 extracts header and body information of the invite message (S28). Here, the URI of the communication terminal that is the sending source and destination of the invite message and the information of the communication media (for example, audio and video) described in SDP in the body of the message are extracted. The invite message analysis unit 20 inputs the extracted information to the routing control unit 24.

  The routing control unit 24 performs routing of the invite message based on the information accumulated in the terminal information accumulation unit 26 and the information extracted from the invite message.

  First, the routing control unit 24 acquires the radio wave intensity information 28 (see FIG. 3) and the selection condition 30a (see FIG. 4A) regarding the radio wave intensity of the incoming communication terminal 40 from the terminal information storage unit 26 (S30). ). Next, the routing control unit 24 determines whether there is a network that satisfies the media request based on the media type of communication established by the invite message (S32).

  Specifically, first, the radio wave intensity required for performing communication using the media described in the routing control unit 24 invite message is obtained from the selection condition 30a regarding the radio wave intensity. For example, when the media information is video, it can be seen from FIG. 4A that the 3G network requires E3 radio field strength and the WLAN network requires E4 radio field strength. Subsequently, it is determined whether or not there is a network that can receive radio waves with the required radio wave intensity in the network to which the receiving communication terminal 40 is connected. The routing control unit 24 determines the radio field intensity of the receiving communication terminal 40 based on the radio field intensity information 28 of the receiving side communication terminal 40 acquired from the terminal information storage unit 26 and the radio field intensity information necessary for each network. Search for networks that exceed strength. Taking the communication terminal A as an example, the radio field intensity in the 3G network is Ea1, so the radio field intensity Ea1 of the communication terminal A is compared with the radio field intensity E3 required for video communication, and if Ea1> E3, 3G The network is determined to satisfy the media request. Similarly, for other networks, it is determined whether or not the media request is satisfied, and a network that satisfies the media request is searched. If there is no network satisfying the media request as a result of this search, the network control device 10 returns a message indicating that communication is impossible to the terminal that sent the invite message (S34).

  When there is a network that satisfies the media request, the network control apparatus 10 determines whether there are a plurality of networks that satisfy the media request (S36). If there is only one network that can satisfy the media request, an invite message is transmitted to the communication terminal 40 through the network (S40). That is, an invite message is created and sent to the IP address of the interface of the network.

  When there are a plurality of networks that satisfy the media request, a network is selected in which the radio field intensity of the communication terminal 40 is much higher than the necessary radio field intensity defined in the selection condition 30a regarding the radio field intensity (S38). Then, the network control device 10 transmits an invite message to the communication terminal 40 through the selected network (S42).

  The network control device 10 and the communication terminal 40 according to the first embodiment of the present invention have been described above.

  The network control device 10 according to the first embodiment stores information for network selection registered from the communication terminal 40 in the terminal information storage unit 26, and the communication terminal 40 based on the stored network selection information. Select the network to send the connection request addressed to. As a result, it becomes possible to select a network that meets the request of the communication terminal 40 on the incoming side of the connection request.

  Further, since the network control apparatus 10 receives the radio wave intensity information transmitted from the communication terminal 40 and stores it in the terminal information storage unit 26, the network control apparatus 10 transmits the radio wave intensity information that can be detected only by the communication terminal 40. Can manage. In this embodiment, when selecting a network, it is determined whether the radio field strength of the communication terminal 40 in each network has a required radio field strength. Whether or not communication is possible can be determined.

  In the above-described embodiment, the radio wave intensity information transmitted from the communication terminal 40 is accumulated in the terminal information accumulation unit 26 and used when selecting a network. However, the radio wave intensity information is not accumulated as it is. Rather, when the radio wave intensity information is received from the communication terminal 40, it is determined whether to register as a terminal connected to the network based on the received radio wave intensity information, and the result of the determination is reflected in the registration information. You can also. That is, if the radio field strength information of a certain network received from the communication terminal 40 is a value exceeding a predetermined threshold, the communication terminal is registered as a terminal connected to the network, and registered if it is less than the predetermined threshold. Perform processing to cancel. As a result, a network having a radio field strength greater than a predetermined threshold is registered and becomes an option when selecting a network, and a network with a radio field intensity equal to or lower than the predetermined threshold can be excluded from the network selection options.

  In the above-described embodiment, the routing control unit 24 of the network control device 10 has been described with respect to a method for selecting a network to transmit a connection request based on the radio field intensity of the communication terminal 40. It is also possible to select a network based on information registered from the communication terminal 40.

  FIG. 10 is a diagram for explaining another example of the operation of the network control apparatus 10. The basic operation flow is the same as that of the network control apparatus 10 described with reference to FIG. 9, but the method of selecting a network by the routing control unit 24 is different. Hereinafter, steps of the network selection method by the routing control unit 24 will be described.

  When receiving the invite message, the network control device 10 extracts the header and body information by the invite message analyzing unit 20 (S28). Here, the URI of the communication terminal 40 that is the sending source and destination of the invite message, and information on the type of communication media (for example, audio and video) described in SDP in the body of the message are extracted. The invite message analysis unit 20 inputs the extracted information to the routing control unit 24.

  The routing control unit 24 performs routing of the invite message based on the information accumulated in the terminal information accumulation unit 26 and the information extracted from the invite message.

  The routing control unit 24 acquires from the terminal information storage unit 26 a selection condition 30b (see FIG. 4B) regarding network characteristics (S42). The routing control unit 24 uses the communication media type established by the invite message and the selection condition 30b regarding the network characteristics based on the information of the communication terminal 40 that is the transmission source and destination of the invite message. Information on the characteristics of the network to be searched is retrieved (S44). For example, when the URI of the called user is U1, the URI of the calling user is S1, and the media type is voice, referring to FIG. 4B, the network to be used is characterized by a network with good sound quality. It is. Then, the routing control unit 24 determines whether there is a network having the searched characteristics. As a result, if there is no network having the searched characteristics, the network control device 10 transmits a message indicating that communication is impossible to the terminal that is the source of the invite message (S46).

  When there is a network that satisfies the searched characteristics, the routing control unit 24 selects the searched network as a network that transmits the invite message. Then, the network control device 10 transmits an invite message through the selected network (S48).

  As described above, by selecting a network based on the characteristics of the network, the user of the receiving communication terminal 40 can select the network based on sound quality and security.

  FIG. 11 is a diagram for explaining another example of the operation of the network control device 10. The basic operation flow is the same as the operation of the network control apparatus 10 described in FIG. In the operation shown in FIG. 11, when there are a plurality of networks satisfying the media information, the network is selected based on the user's request instead of selecting the network based on the radio wave intensity as described in FIG. 9. This is different from the operation of the network control device 10. When there are a plurality of networks satisfying the media information (YES in S36), for example, the network having the characteristics requested by the called user is selected based on the selection condition 30b regarding the characteristics of the network registered from the communication terminal 40. (S50).

  The other examples of the network selection operation by the network control apparatus 10 have been described above, but various network selection methods other than those described above can be considered. By variously setting the network selection information stored in the terminal information storage unit 26 of the network control device 10, the network on which the communication terminal 40 receives incoming calls can be flexibly selected.

  Next, the network control device 10 and the communication terminal 40 according to the second embodiment of this invention will be described. The communication terminal 40 according to the second embodiment is a communication terminal 40 that sets whether to register as a terminal connected to the network or to cancel the registration based on the radio wave intensity received through the network. Note that the environment to which the network control device 10 and the communication terminal 40 of the second embodiment are applied is the same as that of the first embodiment (see FIG. 2).

  FIG. 12 is a diagram illustrating a configuration of the communication terminal 40 according to the second embodiment. The communication terminal 40 according to the second embodiment has the same basic configuration as the communication terminal 40 according to the first embodiment, but instead of the radio wave intensity change boundary value accumulation unit 48, radio wave intensity boundary value accumulation is performed. The difference is that the portion 66 is provided.

  FIG. 13 is a diagram illustrating an example of data stored in the radio wave intensity boundary value storage unit 66. The radio wave intensity boundary value accumulating unit 66 accumulates information on radio wave intensity necessary for maintaining communication. The radio wave intensity information is set for each network to which the communication terminal 40 can be connected. Referring to FIG. 13, the radio field intensity is E1 in the 3G network, and the radio field intensity is E2 in the WLAN network.

  The connection control unit 50 has a function of transmitting a request message for registering connection to the network or canceling registration. The created request message is a SIP register message. The connection control unit 50 compares the radio field intensity detected by the radio field intensity detection unit 64 with the radio field intensity boundary value stored in the radio field intensity boundary value storage unit 66, and when the detected radio field intensity exceeds the boundary value. A connection registration request message is transmitted, and a connection release request message is transmitted when the detected radio field intensity is below the boundary value.

  Next, the network control apparatus 10 will be described. FIG. 14 is a diagram illustrating a configuration of the network control device 10 according to the second embodiment. The network control device 10 includes a message transfer unit 12, a message analysis unit 14, a routing control unit 24, and a terminal location information storage unit 32. The network control device 10 used in the second embodiment is a normal network control device.

  Next, operations of the communication terminal 40 and the network control device 10 according to the second embodiment will be described.

  FIG. 15 is a diagram illustrating an operation in which the communication terminal 40 transmits a request message related to connection registration. First, the communication terminal 40 detects the intensity of the radio wave received through the network by the radio wave intensity detector 64 (S60). The radio field intensity detection unit 64 inputs the detected radio field intensity information to the connection control unit 50.

  The connection control unit 50 acquires the boundary value stored in the radio wave intensity boundary value storage unit 66 (S62), and compares the acquired boundary value with the detected radio wave intensity (S64). When the detected radio field intensity exceeds the boundary value, the connection control unit 50 further determines whether or not the communication terminal 40 has already been registered for connection to the network in which the radio field intensity is detected (S66). If the connection is already registered, the communication terminal 40 proceeds to step S60 for acquiring the radio wave intensity information. If the connection is not yet registered, the connection control unit 50 creates a message for registering connection to the network (S68), and transmits the created message to the network control device 10 (S74). Here, a message created by the connection control unit 50 will be described.

  FIG. 16A shows a message requesting connection registration to the network. The message created by the connection control unit 50 is a SIP register message. The header includes items “From” and “To” describing the URI of the communication terminal 40 of the transmission source, an item “Contact” describing the IP address of the registered wireless interface, and information regarding the period for requesting registration. And an item “Expires” to be described. No value is described in “Expires”, but this means that a connection is registered without setting a period.

  Next, the operation of the communication terminal 40 when the detected radio field intensity is equal to or lower than the boundary value as a result of the comparison between the acquired boundary value and the detected radio field intensity (NO in S64) will be described. In this case, the connection control unit 50 further determines whether or not the communication terminal 40 has already been registered for connection to the network in which the radio wave intensity is detected (S70). If the connection registration to the network is not performed, the communication terminal 40 proceeds to step S60 for acquiring the radio wave intensity information. When the connection registration to the network has already been performed, the connection control unit 50 creates a message for canceling the connection registration to the network (S72), and transmits the created message to the network control device 10 (S74). Here, a message created by the connection control unit 50 will be described.

  FIG. 16B is a diagram illustrating a message for requesting the network to cancel connection registration. The message created by the connection control unit 50 is a SIP register message. Each item of the header is the same as the message for connection registration. In a message requesting release of connection registration, 0 is described as the value of Expires. This message can release the connection to the network.

  FIG. 17 is a diagram for explaining the operation of the network control apparatus 10. The network control device 10 receives the message by the message transfer unit 12 (S80). The message transfer unit 12 inputs the received message to the message discrimination control unit 16. The network control device 10 determines the type of the received message by the message determination control unit 16 (S82). Depending on the determination result, the processing performed by the network control device 10 is divided into two. When the received message is a register message, the network control device 10 performs processing related to registration of the communication terminal with the network. When the received message is an invite message, the network control device 10 Processing to connect communication with the communication terminal 40 is performed.

  First, a case where the received message is a register message will be described. The message analysis unit 14 extracts the header and body information of the register message (S84). Here, the URI of the communication terminal 40 and the radio interface IP address supported by the terminal are extracted. The message analysis unit 14 stores the extracted information in the terminal location information storage unit 32, and performs registration or deregistration of the communication terminal 40 (S86).

  Next, a case where the received message is an invite message will be described. The message analysis unit 14 extracts the header information of the invite message (S88) and inputs it to the routing control unit 24. Here, the URI information of the communication terminal 40 that is the source and destination of the invite message is extracted.

  When receiving the information from the message analysis unit 14, the routing control unit 24 acquires the information of the communication terminal 40 on the incoming side from the terminal location information storage unit 32 (S90). Then, based on the terminal location information 32, the routing control unit 24 selects a network to be used for communication from the network to which the incoming communication terminal 40 is connected (S92). Then, the network control unit creates and transmits a register message for transmission through the selected network (S94).

  The communication terminal 40 and the network control device 10 according to the second embodiment have been described above.

  The communication terminal 40 according to the second embodiment detects the strength of a radio wave received through the network, compares the detected radio wave strength with a predetermined boundary value, and determines whether to register a connection to the network. To do. The boundary value stores information on the radio field intensity necessary to maintain communication, and if the field intensity is greater than the boundary value, the connection to the network is registered, so stable communication is performed by the registered network. be able to.

  As described above, the present invention selects a network for communication performed in a connection established by a connection request based on network selection information registered from a communication terminal on the called side. As a network control device that controls the connection to a communication terminal that can be connected to a plurality of networks having different communication methods, it has an excellent effect of being able to select a device that meets the needs of the receiving user. is there.

The figure which shows the structure of the network control apparatus of 1st Embodiment The figure which shows the environment where the network control apparatus and communication terminal of embodiment are applied The figure which shows the example of the electromagnetic wave intensity information accumulate | stored in the terminal information storage part (A) The figure which shows the example of the network selection information accumulate | stored in the terminal information storage part (b) The figure which shows the example of the network selection information accumulate | stored in the terminal information storage part The figure which shows the structure of the communication terminal of 1st Embodiment The figure which shows operation | movement of the communication terminal of 1st Embodiment Diagram showing the sequence of register messages The figure which shows the example of the register message transmitted from the communication terminal The figure which shows operation | movement of the network control apparatus of 1st Embodiment The figure which shows the other example of operation | movement of the network control apparatus of 1st Embodiment. The figure which shows the other example of operation | movement of the network control apparatus of 1st Embodiment. The figure which shows the structure of the communication terminal of 2nd Embodiment. The figure which shows the example of the data accumulated in the field intensity boundary value accumulation part The figure which shows the structure of the network control apparatus of 2nd Embodiment. The figure which shows operation | movement of the communication terminal of 2nd Embodiment (A) The figure which shows the example of the register message transmitted from the communication terminal (b) The figure which shows the example of the register message transmitted from the communication terminal The figure which shows operation | movement of the network control apparatus of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Network controller 12 Message transfer part 14 Message analysis part 16 Message discrimination | determination control part 18 Register message analysis part 20 Invite message analysis part 22 Message preparation part 24 Routing control part 26 Terminal information storage part 28 Signal strength information 30 Network selection information 32 Location information 40 Communication terminal 42 Upper layer 44 Application logic 46 Application profile 48 Radio wave intensity change boundary value accumulation unit 50 Connection control unit 52 User interface 54 Lower layer 56 Communication protocol control unit 58 Wireless interface control unit 60 3G interface 62 WLAN interface 64 radio wave Strength detector 66 Radio wave intensity boundary value storage unit

Claims (10)

A network control method for controlling connection to a communication terminal connectable to a plurality of networks having different communication methods by a network control device ,
Receiving a SIP register message describing radio field intensity information from a communication terminal;
Extracting the field strength information from the SIP register message;
Storing the extracted signal strength information in the terminal information storage unit;
Receiving a SIP invite message describing communication media information and destination communication terminal information from the communication terminal;
Extracting the communication media information and the destination communication terminal information from the SIP invite message;
Read out the radio field intensity of a plurality of networks connectable to the destination communication terminal from the terminal information storage unit, based on the read radio field intensity and the necessary radio field intensity set for the communication medium, Routing the invite message; and
A network control method comprising:   The step of routing the invite message reads information on necessary radio field intensity corresponding to the communication medium from a storage unit storing information on necessary radio field intensity set for each communication medium. The network control method according to claim 1, wherein routing is performed using the information. The step of routing the invite message comprises:
Determining whether there is a network capable of receiving radio waves at the required radio field intensity based on the radio field intensity of the destination communication terminal;
The network control method according to claim 1 or 2. When there is no receivable network, a message indicating that communication is impossible is returned to the communication terminal that is the source of the invite message
The network control method according to claim 3. If there are multiple receivable networks, select the network that greatly exceeds the required radio field strength.
The network control method according to claim 3. A network control device for controlling connection to a communication terminal connectable to a plurality of networks having different communication methods,
A receiving unit for receiving, via any one of the plurality of networks, a SIP register message describing radio field intensity information and a SIP invite message describing communication media information and destination communication terminal information;
A register message analysis unit for extracting information on the radio field intensity from the register message;
A terminal information accumulating unit for accumulating information on the radio field intensity extracted by the register message analyzing unit;
An invite message analysis unit that extracts information of the communication medium and information of the destination communication terminal from the invite message;
Read out the radio field intensity of a plurality of networks connectable to the destination communication terminal from the terminal information storage unit, based on the read radio field intensity and the necessary radio field intensity set for the communication medium, A routing controller that routes invite messages;
A network control device comprising: The terminal information storage unit stores necessary radio wave intensity information set for each communication medium,
The network control device according to claim 6, wherein the routing control unit reads information on radio field intensity corresponding to the communication medium from the terminal information storage unit, and performs routing using the read radio field intensity information. A communication connection control method by a communication terminal connectable to a plurality of networks having different communication methods,
Detecting the intensity of radio waves received by the communication terminal through a plurality of networks having different communication methods;
When the communication terminal changes the radio field intensity exceeding a predetermined threshold, creating a SIP register message describing the radio field intensity information;
The communication terminal transmits the SIP register message to a network control device that performs connection control by the method according to claim 1 ;
A communication connection method comprising: A communication terminal that can be connected to a plurality of networks with different communication methods,
A radio wave intensity detector that detects the intensity of radio waves received through a plurality of networks with different communication methods;
A connection control unit that creates a SIP register message describing the information of the radio field intensity when the radio field intensity detected by the radio field intensity detector exceeds a predetermined threshold;
A transmitter for transmitting the SIP register message to the network control device according to claim 6 ;
A communication terminal comprising: A communication terminal that can be connected to a plurality of networks with different communication methods,
A radio wave intensity detector that detects the intensity of radio waves received through a plurality of networks with different communication methods;
A boundary value accumulating unit for accumulating the boundary value of the change width of the radio wave intensity;
When the width of the change in radio field intensity detected by the radio field intensity detection unit is compared with the boundary value stored in the boundary value storage unit, and the width of the change in radio field intensity exceeds the boundary value, A connection control unit for creating a SIP register message describing the information of the radio field intensity;
A transmitter for transmitting the SIP register message to the network control device according to claim 6 ;
A communication terminal comprising:

Images