WO2005069674A1

WO2005069674A1 - Network control apparatus and communication terminal

Info

Publication number: WO2005069674A1
Application number: PCT/JP2004/019347
Authority: WO
Inventors: Ming Qiang Xu; Sachiko Takeshita; Maki Amishima; Kentaro Takei
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2004-01-14
Filing date: 2004-12-24
Publication date: 2005-07-28
Also published as: JP4477884B2; JP2005203926A

Abstract

A network control apparatus (10) for controlling connection to a communication terminal (40) capable of connecting to a plurality of networks having different communication systems, comprising a terminal information storage part (26) for storing network selection information registered by the communication terminal (40) so as to select one of the plurality of networks; a message transfer part (12) for receiving a request of connection of communication addressed to the communication terminal; and a routing control part (24) for selecting, based on the network selection information stored in the terminal information storage part (26), a network for the communication connected by the connection request received by the message transfer part (12); wherein the connection request is transmitted via the network as selected by the routing control part (24).

Description

Specification

Network control device and communication terminal

Technical field

The present invention relates to a network control device that controls connection to a communication terminal connectable to a plurality of networks having different communication methods.

Background art

[0002] Various protocols for establishing, modifying, and terminating a multimedia session on an IP network have been proposed. One of these protocols is SIP (Session Initiation on Protocol)

[0003] SIP is an application layer signaling protocol. Proposed by the working group of the IETF (Internat Engineering Task Force) and is currently being standardized in RFC3261. Services that can be implemented with SIP include a variety of services such as video conferencing, telephone calls, instant messages, and presence. The 3GPP (The Third Generation Project) has decided to use SIP to establish a network-side session for next-generation mobile communication systems.

[0004] In a standard SIP-based communication system, a communication terminal that is the initiator of a session transmits a session start message, and the message is received by a SIP proxy. Then, the SIP proxy routes the session start message to the communication terminal on the receiving side based on the destination described in the standard field of the header of the received session start message.

[0005] A communication system capable of selecting a communication terminal of a communication destination based on a caller's user's intention is disclosed in JP-A-2002-335267, pp. 5, 6 and FIG. ing . This communication system is a communication system constructed using SIP, and has a calling endpoint, a called endpoint, and a server. In this communication system, a location server and a database are connected to a server. The location server has location information that is used for routing calls between the calling and called endpoints. The database contains the attributes of the communication terminals included in the called network. Sex information is included.

[0006] In this communication system, the calling endpoint has information on the called endpoint in advance. When starting communication using this communication system, the calling end point creates and transmits a call start message in which main routing information is added to standard routing information called header routing information. The main unit routing information includes information related to the intention of the user (caller) having the calling communication terminal. For example, we talked to a salesperson who was familiar with washing machines! If / ヽ and the user of the calling communication terminal wish, the keyword indicating the attribute of “washing machine” ヽぅ called terminal is described in the main body routing information.

[0007] Upon receiving the call start message transmitted from the calling endpoint, the server determines a destination address based on the routing information included in the call start message. More specifically, the server estimates the intention of the caller based on a keyword included in the main body routing information, and obtains an address to be routed in a database. Then, the server transmits a call start message to the obtained address.

[0008] Thereby, in the communication system described in the above patent document, a call start message can be routed to a terminal based on a caller's intention. For example, if the standard routing information is the address of a general electric company and the routing information associated with the caller is "washing machine", the electric company is determined based on the location server and database. It is possible to connect the call to a terminal of a skilled sales person who can answer questions about the washing machine.

Disclosure of the invention

Problems to be solved by the invention

[0009] 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, a communication terminal that can support a network having a different communication method with one communication terminal has 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 status of the network to which the communication terminal is connected. In the future, when such a user receives an incoming call, the network to be used will be selected in consideration of the radio wave condition and the communication partner. It is desired.

[0010] However, in the communication system described in the above Patent Document, routing is performed based on the intention of the user on the calling side, but the request on the receiving side is not considered. In addition, although the radio wave reception status of the receiving terminal constantly changes, the status of the receiving terminal is not considered in the above-described communication system. Japanese Patent Application Laid-Open No. 8-340308 discloses a communication method for selecting a data transfer speed by using radio wave intensity detected by a communication terminal. However, this communication method also does not take into account the radio wave intensity of the communication terminal on the receiving side. That is, in the conventional communication system, when there are a plurality of candidates for a network that can receive a call, the communication terminal on the call receiving side considers the radio wave reception status of the communication terminal on the call receiving side, for example, radio wave intensity. As a result, poor reception of radio waves and the possibility of receiving incoming calls via the network.

[0011] In view of the above background, an object of the present invention is to provide a network control device capable of selecting a network to start a connection in consideration of a request of a user of a called terminal or a radio wave condition of the called terminal. I do.

Means for solving the problem

[0012] A network control device of the present invention is a network control device for controlling connection to a communication terminal connectable to a plurality of networks having different communication schemes, and selects one of the plurality of networks. Network connection information storing means for storing information registered from the communication terminal, a connection request receiving means for receiving a connection request for communication addressed to the communication terminal, and a connection request received by the connection request receiving means. The network selection means for selecting a network for communication to be performed by the established connection based on the information stored in the network selection information storage means, and the communication through the network selected by the network selection means. Connection request transmitting means for transmitting the connection request to a terminal.

[0013] According to this configuration, a network for communication performed in the connection established by the connection request is selected based on the network selection information registered from the communication terminal on the receiving side. It is possible to select one that meets the needs of the side user. Further, the user of the communication terminal may select a network to be used for incoming calls, for example, It can be set based on the communication partner, communication type, radio wave reception status of the communication terminal, network communication speed and security, etc.

[0014] Further, the network selection information storage means stores information on the intensity of radio waves received by the communication terminal through each of a plurality of networks, and the network selection means is stored in the network selection information storage means. The network may be selected based on the information on the received radio wave intensity.

[0015] With this configuration, it is possible to select a network having a high possibility of communicating with the communication terminal based on the radio wave intensity. As a result, the number of retransmissions of the connection request can be reduced to contribute to alleviation of network congestion, and the possibility of disconnecting the communication connection after the communication connection can be reduced.

[0016] Further, the network selection information storage means stores information on radio field intensity required for communication for each communication type, and the network selection means is established by a connection request received by the connection request reception means. The type of communication to be performed in the connection is determined, and the network may be selected based on the signal strength required for communication of the determined type and information on the signal strength of the communication terminal! /.

[0017] According to this configuration, it is possible to select a network having a radio field intensity necessary for communication performed in the connection established by the connection request, so that communication after connection can be performed smoothly. The communication type is information on communication contents such as multimedia communication and voice communication.

[0018] Further, the network selection information storage means stores information related to security of a network required for communication, and the network selection means stores a network based on the information related to security stored in the network selection information storage means. Select a little.

[0019] 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.

[0020] Further, the network selection information storage means stores the information on security in association with information on a terminal from which the connection request has been transmitted, and the network selection means stores the connection request received by the connection request reception means. Force Information on security required for communication with the terminal of the transmission source may be extracted from the network selection information storage means, and a network may be selected based on the extracted information on security. ! / ,.

[0021] With this configuration, it is possible to select a called-side network having communication security that the user of the called-side communication terminal desires to secure according to the communication partner.

[0022] Further, the network selection information storage means stores the information on security for each communication type, and the network selection means executes a connection established by a connection request received by the connection request receiving means. It is also possible to determine the type of communication to be performed, extract information related to security required for communication of the type of communication from the network selection information storage unit, and select a network based on the extracted information related to security! 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 in accordance with the communication type.

[0024] Further, the network selection information storage means stores information relating to a communication speed of a network required for communication, and the network selection means stores the information based on the communication speed stored in the network selection information storage means. Then, the network may be selected.

[0025] With this configuration, it is possible to select a network on the called side having a communication speed of communication desired by the user of the communication terminal on the called side.

[0026] Further, the network selection information storage means stores information on the communication speed in association with information on a terminal from which a connection request is transmitted, and the network selection means stores the connection request received by the connection request reception means. The information on the source terminal is extracted, the information on the communication speed required for communication with the source terminal is extracted from the network selection information storage means, and the network is extracted based on the extracted information on the communication speed. You can choose! /.

[0027] With this configuration, it is possible to select a network on the receiving side having a communication speed of communication desired by the user of the communication terminal on the receiving side according to the communication partner.

[0028] Further, the network selection information storage means stores the information regarding the communication speed for each communication type. The network selection means determines the type of communication performed in the connection established by the connection request received by the connection request receiving means, and obtains information on the communication speed required for communication of the communication type. A network may be selected based on the information on the communication speed extracted from the network selection information storage means.

[0029] According to this configuration, a network having a communication speed necessary for communication performed in the connection established by the connection request can be selected, so that communication after connection can be performed smoothly. The communication type is information on communication contents such as multimedia communication and voice communication.

[0030] A network control device according to another aspect 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 schemes, wherein the network control device controls the connection through the plurality of networks. The communication terminal receives the radio wave intensity information related to the radio wave intensity received by the communication terminal based on the radio wave intensity information received by the communication terminal. A registration processing means for registering or canceling the registration as a terminal connected to one network, and transmitting a connection request addressed to the communication terminal through a network selected from the networks registered by the registration processing means. And a connection request transmission means for performing the connection.

[0031] With this configuration, the radio wave intensity information that can be detected only by the communication terminal can be managed by the network control device. In addition, since the ability to register as a terminal connected to the network is determined based on the radio field strength information, it is possible to register an appropriate network as a candidate for a network used for communication.

[0032] Further, based on the radio field intensity information received by the radio field intensity information receiving unit, the registration processing unit is configured to, when the radio field intensity of the communication terminal exceeds a predetermined threshold, be set to the communication terminal May be registered, and the registration of the communication terminal may be canceled when the radio field intensity of the communication terminal is equal to or less than the threshold.

[0033] With this configuration, a network having a high signal strength is registered, and the network registered as a candidate has a high possibility of communication connection. Therefore, the number of retransmissions of connection requests can be reduced to alleviate network congestion, and communication can be performed after communication is connected. The possibility of disconnection of the communication connection can be reduced.

[0034] Further, the radio wave intensity information receiving means receives a SIP message including the radio wave intensity information, and the registration processing means transmits the body strength of the SIP message received by the radio wave intensity information receiving means to the radio wave intensity information. You can extract it.

[0035] Since additional information can be described in a message body in SIP, it is preferable to transmit information on radio wave intensity using a SIP message.

[0036] A communication terminal of the present invention is a communication terminal connected to a network control device that selects a network to be used for an incoming call to a communication terminal from a plurality of networks of different communication systems based on the radio wave intensity of the communication terminal. Radio wave intensity detecting means for detecting the intensity of radio waves received through a plurality of networks having different communication systems, and a radio wave intensity detected by the radio wave intensity detecting means when the radio wave intensity exceeds a predetermined threshold value. Means for transmitting radio field intensity information to the network control device.

[0037] With this configuration, when the change in the radio wave intensity is small, the radio wave intensity information is not transmitted, so that the number of transmissions of the radio wave intensity information is limited, which alleviates network congestion. In addition, since the radio wave intensity information is transmitted to the network control device when the change in the radio wave intensity is large, the radio wave intensity information useful for selecting a network can be notified to the network control device.

[0038] A communication terminal according to another aspect of the present invention includes a radio wave intensity detecting means for detecting the intensity of radio waves received through a plurality of networks having different communication methods, and a radio wave intensity detecting means. Determining means for determining whether to use the one network based on the strength of the radio wave, and registering the communication terminal as a terminal connected to the network based on a result of the determination by the determining means; Or a request message transmitting means for transmitting a request message for canceling the registration to a network control device for controlling connection to the network.

[0039] According to this configuration, connection registration is performed for a network determined to be used according to the radio wave intensity, so that an incoming call can be received through an appropriate network.

[0040] Further, the determining means determines that the one network is used when the radio wave intensity detected by the radio wave strength detecting means exceeds a predetermined threshold value, If the radio field intensity detected by the radio field intensity detection means is equal to or less than the threshold, it may be determined that the one network is not used.

[0041] With this configuration, a network having a radio field intensity exceeding the threshold 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 connection requests, thereby contributing to alleviation of network congestion, and to reduce the possibility of communication connection being disconnected even after communication connection.

[0042] Further, the request message transmitting means may transmit the request message when a result of the determination by the determining means as to whether or not to use the one network changes.

[0043] According to this configuration, the request message is transmitted only when the determination result of the use or non-use of the network changes, so that the number of times the request message is transmitted can be reduced.

[0044] The request message transmitting means may transmit a SIP message including information on whether to register the communication terminal in the network or whether to cancel the registration.

[0045] 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 to 0 in the header of the register message.

[0046] A communication connection method according to the present invention is a communication connection method for a communication terminal connectable to a plurality of networks having different communication schemes, wherein the network control device controls the communication terminal. A connection request receiving step of receiving a connection request from the communication terminal; and a network for communication performed by a connection established by the connection request received in the connection request reception step in the connection request receiving step. A network selection step of selecting based on information for selecting one of the plurality of networks, and the network control device transmits to the communication terminal through the network selected in the network selection step. Transmitting a connection request.

With this configuration, a network for communication performed in a connection established by a connection request is selected based on network selection information registered from a communication terminal on the receiving side. Therefore, it is possible to select a network that more closely matches the needs of the called user as the called network. In addition, the user of the communication terminal can set a network to be used for receiving a call based on, for example, a communication partner and a communication type, a radio wave reception state of the communication terminal, a communication speed and security of the network, and the like. Note that the above-described various configurations of the network control device of the present invention can be applied to the communication connection method of the present invention.

[0048] The method for registering connection to a network according to the present invention is a method for registering a communication terminal connectable to a plurality of networks having different communication schemes as a terminal connected to the network. The apparatus receives radio wave intensity information on the radio wave intensity received by the communication terminal through the plurality of networks in the radio wave intensity information receiving step of receiving from the communication terminal and the radio wave intensity information receiving step. A registration processing step of registering the communication terminal as a terminal connected to the one network based on the radio field intensity information; or a registration processing step of canceling the registration. The registered network is a candidate for a network used for transmitting a connection request to the communication terminal.

With this configuration, the radio wave intensity information that can be detected only by the communication terminal can be managed by the network control device. In addition, since the ability to register as a terminal connected to the network is determined based on the radio field strength information, it is possible to register an appropriate network as a candidate for a network used for communication. Note that the above-described various configurations of the network control device of the present invention can be applied to the method of registering connection to a network of the present invention.

[0050] In the method for registering connection to a network according to the present invention, the communication terminal detects a radio wave intensity detecting step of detecting radio wave intensity received through a plurality of networks having different communication methods; The communication terminal determines whether or not to use the one network based on the strength, and the communication terminal is connected to the network based on a result of the determination in the determination step. A request message transmitting step of transmitting a request message for registering as a terminal or canceling the registration to a network control device controlling connection to the network. [0051] According to this configuration, connection registration is performed for a network determined to be used according to the radio wave intensity, so that an incoming call can be received through an appropriate network. It should be noted that the above-described various configurations of the communication terminal of the present invention can be applied to the method for registering connection to a network according to the present invention.

[0052] According to the present invention, the communication terminal of the called side also selects a network for communication performed on a connection established by a connection request based on the registered network selection information. In the overlapped area, there is an excellent effect that a network that meets the demands of the called user can be selected as the called network.

Brief Description of Drawings

FIG. 1 is a diagram showing a configuration of a network control device according to a first embodiment.

FIG. 2 is a diagram showing an environment in which a network control device and a communication terminal according to the embodiment are applied;

FIG. 3 is a diagram showing an example of radio field intensity information stored in a terminal information storage unit

[4A] FIG. 4A is a diagram showing an example of network selection information stored in the terminal information storage unit. [4B] FIG. 4B is a diagram showing an example of network selection information stored in the terminal information storage unit.

FIG. 5 is a diagram showing a configuration of a communication terminal according to the first embodiment.

FIG. 6 is a diagram showing an operation of the communication terminal according to the first embodiment.

[FIG. 7] FIG. 7 is a diagram showing a sequence of a register message.

FIG. 8 is a diagram showing an example of a register message transmitted from a communication terminal;

FIG. 9 is a diagram showing an operation of the network control device according to the first embodiment;

FIG. 10 is a diagram showing another example of the operation of the network control device according to the first embodiment.

FIG. 11 is a diagram showing another example of the operation of the network control device according to the first embodiment.

FIG. 12 is a diagram showing a configuration of a communication terminal according to a second embodiment.

FIG. 13 is a diagram showing an example of data stored in a radio field intensity boundary value storage unit

FIG. 14 is a diagram illustrating a configuration of a network control device according to a second embodiment;

FIG. 15 is a diagram showing an operation of the communication terminal according to the second embodiment.

[FIG. 16A] FIG. 16A is a diagram showing an example of a register message transmitted from a communication terminal. [FIG. 16B] FIG. 16B is a diagram showing an example of a register message transmitted by a communication terminal.

FIG. 17 is a diagram showing the operation of the network control device according to the second embodiment.

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 the network control device 10 according to the first embodiment. Before describing the configuration of the network control device 10 of the first embodiment, an environment in which the network control device 10 and the communication terminal 40 of the embodiment are applied will be described.

FIG. 2 is a diagram showing an environment to which the network control device 10 and the communication terminal 40 according to the embodiment of the present 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.

[0057] The communication terminal 40 is a terminal that can be connected to a plurality of different communication networks. Here, communication terminal 40 is connectable to a 3G network and a WLAN network. The communication terminal 40 is managed by one number. That is, regardless of which network is used for communication, the communication terminal 40 can be accessed with the same number. 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 connectable to a network, or an Internet home appliance. The communication terminal 70 is connected to an ISP. Note that the communication terminal 70 may be connected by another carrier other than the ISP.

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

[0059] Referring to FIG. 1, the network control device 10 will be described. Network control device 10 is a session management device for interworking 3G networks and WLAN networks. The network control device 10 has a SIP proxy, and establishes, disconnects, and routes sessions using SIP.

As shown 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 for storing information (communication charges, bandwidth, etc.) regarding the network.

[0061] The message transfer unit 12 has a function of performing a process of creating a transmission message as a packet and a process of creating a received packet as a message.

[0062] 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 discrimination control unit 16 that determines the type of the SIP message and controls the operation associated therewith, and a register message analysis unit that extracts the header and body of the register message and transmits the extracted message to the terminal information storage unit 26 18, an Innote message analyzer 20 that extracts SDP (Session Description Protocol) information included in the body of the invite message and sends it to the routing controller 24, and a message generator 22 that creates a transmission message. Have. 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 the information stored in the terminal information storage unit 26. Since the network selection conditions described below are stored in the terminal information storage unit 26, by performing routing based on the network selection conditions, it is possible to perform routing using a network according to the request of the called terminal.

[0064] The terminal information storage unit 26 stores information on radio wave intensity received by the communication terminal 40 (radio wave intensity information) 28, information on conditions for selecting a network (selection condition information) 30, and location information on the communication terminal 40. It has a function to accumulate 32. The location information 32 of the communication terminal 40 is information on the location where the communication terminal 40 exists, and is the same as the location information stored by a normal network control device. Signal strength information 28 and selection condition information Reference numeral 30 denotes 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 showing 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 on the intensity with which the communication terminal 40 receives radio waves through the respective networks. In the example shown in FIG. 3, the radio wave intensity of the communication terminal A in the 3G network is Eal, and the radio wave 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.

FIGS. 4A and 4B are diagrams showing examples of the selection condition information 30. FIG. FIG. 4A is a diagram showing an example of a selection condition 30a relating to radio field intensity, and FIG. 4B is a diagram showing an example of a selection condition 30b relating to network characteristics.

[0067] 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. The required radio field intensity information is set according to each network. For example, in the case of voice communication, the required signal strength in a 3G network is E1, and in a WLAN network it is E2. Based on these conditions, a network that satisfies the required signal strength will be selected.

As shown in FIG. 4B, in the selection condition 30b regarding the network characteristics, information on the network characteristics to be selected according to the called user URI, the calling user URI, and the communication medium is set. For example, if the receiving user URI is Ul, the calling 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 relating to the characteristics of the network is set based on information from the communication terminal 40. Note that the present invention may include a mode in which the selection condition information 30 is updated by the notification of the user power of the communication terminal 40. 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 details at the time of purchase and the set network selection condition information 30. Alternatively, when the communication terminal 40 is registered as a terminal connected to the network, it is possible to notify the selection condition.

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 It has a simplified 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. Further, the communication terminal 40 has a radio field intensity detection unit 64 for detecting the radio field intensity between the upper layer 42 and the lower layer 54.

[0070] The communication terminal 40 includes, in the upper layer 42, an application logic unit 44 and an application profile unit 46 constituting a normal application, a radio field intensity boundary value storage unit 48, a connection control unit 50, and a user interface 52. Having. The communication terminal 40 has 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.

[0071] The radio wave intensity change boundary value accumulating section 48 accumulates information on the boundary value of the radio wave intensity change width used in the network control device 10 to determine whether or not to transmit the radio wave intensity information.

[0072] The connection control unit 50 has a function of determining whether or not to transmit information on the radio field intensity to the network control device 10, and creating a register message based on the determination result. The determination as to whether or not to transmit the radio wave intensity information is performed by comparing the change width of the radio wave intensity detected by the radio wave intensity detection unit 64 with the boundary value of the radio wave intensity change.

[0073] The communication protocol control unit 56 has a function of controlling a communication protocol in the wireless interface. The communication protocol control unit 56 corresponds to the transport layer and the 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.

[0075] 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, 62 correspond to the physical layer of the OSI reference model.

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

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

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

When the change width of the radio field intensity exceeds the radio field intensity change boundary value, communication terminal 40 creates a message for notifying the information of the radio field intensity by message creation section 22 (S16). Here, a message is created in which information on the radio field intensity is described in the SIP register message. 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 upon receiving the register message, the network control device 10 registers the communication terminal 40 of the transmission source and transmits 200OK as a success response. . Thus, the sequence of the register message is completed. By including the radio wave intensity information in the register message, the radio wave intensity information can be transmitted to the network control device 10 without using a new message.

[0081] If it is determined in step S14 that the detected range of the change in the radio wave intensity is equal to or smaller than the radio wave intensity change boundary value, the communication terminal 40 does not transmit the radio wave intensity information. The process proceeds to step S10 for acquiring radio field intensity information. 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 is reduced, and the processing load on the communication terminal 40 is reduced. As much as possible, it can help alleviate network congestion.

FIG. 8 is a diagram showing a register message describing radio field intensity information. In the body of the register message, information on the radio wave intensity is described. In SIP, the body is a standard This part can describe information extended from information. The header of the register message includes “From” and “To” t, which describe the URI of the communication terminal 40 of the transmission source, an item called “Contact”, which describes the IP address of the registered radio interface, and And “Expires” in which information on the period 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 showing 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 uses the message determination control unit 16 to determine the type of the received message (S22). The processing performed by the network control device 10 according to this determination result is divided into two. If the received message is a register message, the network control device 10 performs processing for storing information on the radio field intensity at the communication terminal 40, and if the received message is a S-invite message, the network control device 10 A process for connecting communication to the destination 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 analyzer 18 extracts the header and body information of the register message (S24). Here, the URI of the communication terminal 40, the wireless interface IP address supported by the terminal, and the radio field intensity information are extracted. The register message analyzer 18 specifies the extracted information communication terminal and network, and stores the radio wave intensity information in the terminal information storage 26 (S26).

Next, a case where the received message is an S-invite message will be described. The network control device 10 inputs the received invite message to the innite message analyzer 20. The invite message analysis unit 20 extracts the header and body information of the invite message (S28). Here, the URIs of the source and destination communication terminals of the Innoit 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. [0086] The routing control unit 24 performs the routing of the Invite message based on the information stored in the terminal information storage unit 26 and the information from which the Invite message decal is also extracted.

First, the routing control unit 24 acquires from the terminal information storage unit 26 the radio field intensity information 28 (see FIG. 3) of the communication terminal 40 on the receiving side and the selection condition 30a (see FIG. 4A) relating to the radio field intensity (see FIG. 4A). S30). Next, the routing control unit 24 determines whether or not there is a network satisfying the media request based on the media type of the communication established by the invite message (S32).

[0088] Specifically, first, the routing control unit 24 obtains a radio field intensity required for performing communication using the media described in the Innotte message from the selection condition 30a regarding the radio field intensity. For example, if the media information is video, referring to Fig. 4A, it can be seen that a 3G network requires E3 signal strength and a WLAN network requires E4 signal strength. Subsequently, it is determined whether or not there is a network that can receive a radio wave at the obtained radio wave strength in a network to which the called communication terminal 40 is connected. The routing control unit 24, based on the radio wave intensity information 28 of the called communication terminal 40 obtained from the terminal information storage unit 26 and the radio wave intensity information required for each network, based on the radio wave intensity of the called communication terminal 40. Search for networks that exceed the required signal strength. Taking communication terminal A as an example, the radio wave intensity on the 3G network is Eal, so the radio wave intensity Eal of communication terminal A is compared with the radio wave intensity E3 required for video communication.If Eal> E3, 3G The network is determined to satisfy the media request. Similarly, for other networks, a determination is made as to whether or not the network satisfies the media request, and a network that satisfies the media request is searched. As a result of this search, if there is no network that satisfies the media request, the network control device 10 returns a message indicating that communication is impossible to the terminal that transmitted the invite message (S34).

If there is a network that satisfies the media request, the network control device 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 via the network (S40). In other words, create and send an Invite message to the IP address of the network interface. To do.

If there are a plurality of networks that satisfy the media request, a network that greatly exceeds the required radio field intensity specified in the selection condition 30a regarding the radio field intensity and radio field intensity of the communication terminal 40 is selected (S38). Then, the network control device 10 transmits an in-notify message to the communication terminal 40 through the selected network (S42).

[0091] The network control device 10 and the communication terminal 40 according to the first embodiment of the present invention have been described above.

[0092] The network control device 10 of the first embodiment stores information for network selection registered from the communication terminal 40 in the terminal information storage unit 26, and based on the stored network selection information. First, a network for transmitting a connection request addressed to the communication terminal 40 is selected. This makes it possible to select a network that meets the needs of the communication terminal 40 on the receiving side of the connection request.

[0093] Also, the network control device 10 receives the radio wave intensity information transmitted from the communication terminal 40 and stores the information in the terminal information storage unit 26. Therefore, the network control device 10 stores the radio wave intensity information that can be detected only by the communication terminal 40. It can be managed by the network controller 10. Then, in the present embodiment, when selecting a network, it is determined whether the radio wave intensity of the communication terminal 40 in each network has a required radio wave intensity. Media communication can be determined.

[0094] In the above-described embodiment, the radio wave intensity information transmitted from the communication terminal 40 is stored in the terminal information storage unit 26 and used when selecting a network, but the radio wave intensity information is stored as it is. When receiving the signal strength information from the communication terminal 40, the communication terminal 40 determines whether or not to register as a terminal connected to the network based on the received signal strength information. Can also be reflected. That is, if the radio field intensity 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 if the information is below the predetermined threshold, the communication terminal is registered. Perform processing to cancel registration. As a result, a network having a signal strength higher than a predetermined threshold is registered and becomes an option when selecting a network, and a network having a signal strength equal to or lower than the predetermined threshold is excluded from network selection options. it can.

In the above-described embodiment, the routing control unit 24 of the network control device 10 performs the power routing control described in the method of selecting a network to transmit a connection request based on the radio wave intensity of the communication terminal 40. The unit 24 can also select a network based on the information registered from the communication terminal 40.

FIG. 10 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 device 10 described with reference to FIG. 9, but the method of selecting a network by the routing control unit 24 is different. Hereinafter, the steps of the network selection method by the routing control unit 24 will be described.

[0097] Upon receiving the invite message, the network control device 10 causes the invite message analyzer 20 to extract header and body information (S28). Here, the URI of the communication terminal 40 of the transmission source and the transmission destination of the Invite message and information of the type of communication media (for example, audio and video) described in the SDP in the body of the message are extracted. The invite message analyzer 20 inputs the extracted information to the routing controller 24.

[0098] The routing control unit 24 performs routing of the Invite message based on the information stored in the terminal information storage unit 26 and the information from which the Invite message has been extracted.

[0099] The routing control unit 24 acquires the selection condition 30b (see FIG. 4B) relating to the characteristics of the network from the terminal information storage unit 26 (S42). Based on the media type of the communication established by the invite message and the information of the source and destination communication terminals 40 of the invite message, the routing control unit 24 selects the network characteristics based on the selection condition 30b related to the characteristics of the network. Then, information on the characteristics of the network to be used is searched (S44). For example, if the URI of the called user is Ul, the URI of the calling user is SI, and the media type is voice, referring to Figure 4B, the network to be used is characterized by a network with good sound quality. is there. Then, the routing control unit 24 determines whether or not there is a network having the searched characteristic. As a result, when there is no network having the searched characteristic, the network control device 10 transmits a message indicating that communication is impossible to the terminal that transmitted the invite message (S46).

[0100] If there is a network that satisfies the searched characteristics, the routing control unit 24 Then, the found network is selected as the network for transmitting the invite message. Then, the network control device 10 transmits an invite message through the selected network (S48).

[0101] As described above, by selecting a network based on the characteristics of the network, the user of the receiving communication terminal 40 can select a 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 device 10 described with reference to FIG. The operation shown in Fig. 11 is explained in Fig. 9 in that when there are multiple networks that satisfy the media information, the network is selected based on the user's request instead of selecting the network based on the signal strength. This is different from the operation of the network control device 10. If there are a plurality of networks that satisfy the media information (YES in S36), for example, a network having the characteristics requested by the called user is selected according to the selection condition 30b relating to the characteristics of the network registered from the communication terminal 40. ( _S50) .

As described above, other examples of the operation of the network selection by the network control device 10 have been described. However, various network selection methods other than those described above are conceivable. By variously setting the network selection information to be stored in the terminal information storage unit 26 of the network control device 10, the communication terminal 40 can flexibly select a network to receive an incoming call.

Next, a description will be given of a network control device 10 and a communication terminal 40 according to a second embodiment of the present invention. The communication terminal 40 according to the second embodiment is a communication terminal 40 for setting whether to register as a terminal connected to the network or to cancel registration based on the radio wave intensity received through the network. . 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 a 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. It differs in having a part 66. FIG. 13 is a diagram illustrating an example of data stored in the radio wave intensity boundary value storage unit 66. The electric wave intensity boundary value accumulating section 66 accumulates information of electric wave intensity necessary for maintaining communication. The radio field intensity information is set for each network to which the communication terminal 40 can connect. Referring to FIG. 13, the signal strength is E1 in the 3G network, and the signal strength is E2 in the WLAN network.

[0107] The connection control unit 50 has a function of registering a connection to the network or transmitting a request message for canceling the registration. The created request message is a SIP register message. The connection control unit 50 compares the radio wave intensity detected by the radio wave intensity detection unit 64 with the radio wave intensity boundary value stored in the radio wave intensity boundary value storage unit 66, and when the detected radio wave intensity exceeds the boundary value. A connection registration request message is sent to the server, and a connection release request message is sent when the detected signal strength is below the boundary value.

Next, the network control device 10 will be described. FIG. 14 is a diagram illustrating a configuration of a 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 for connection registration. First, the communication terminal 40 detects the intensity of the radio wave received through the network by the radio wave intensity detection unit 64 (S60). Then, the radio wave intensity detector 64 inputs the detected radio wave intensity information to the connection controller 50.

[0111] The connection control unit 50 acquires the boundary value stored in the radio wave intensity boundary value accumulation unit 66 (S62), and compares the acquired boundary value with the detected radio wave intensity (S64). If the detected radio wave intensity exceeds the boundary value, the connection control unit 50 further determines whether or not the network that has detected the radio wave intensity is already registered for connection with the communication terminal 40 (S66). If the connection has already been registered, the communication terminal 40 proceeds to step S60 of acquiring radio field intensity information. If the connection has not been registered, the connection control unit 50 registers the connection to the network. The message is created (S68), and the created message is transmitted to the network controller 10 (S74). Here, the message created by the connection control unit 50 will be described.

FIG. 16A is a diagram showing a message requesting connection registration to the network. The message created by the connection control unit 50 is a SIP register message. The header requests registration from “From” and “To” t, which describe the URI of the communication terminal 40 of the transmission source, and “Contact”, which describes the IP address of the registered radio interface. An item “Expires” in which information about a period is described. "Expires" has no value, which means that the connection is registered for an indefinite period.

[0113] Next, as a result of comparing the acquired boundary value with the detected radio wave intensity, if the detected radio wave intensity is equal to or lower than the boundary value (NO in S64), the operation of the communication terminal 40 will be described. explain. 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 from which the radio field intensity has been detected (S70). If the connection to the network has been registered, if not, the communication terminal 40 proceeds to step S60 of acquiring radio field intensity information. If the connection to the network has already been registered, 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, the message created by the connection control unit 50 will be described.

FIG. 16B is a diagram showing a message 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 the message requesting connection registration cancellation, 0 is described as the Expires value. This message allows you to disconnect from the network.

FIG. 17 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 (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). The processing performed by the network control device 10 according to this determination result is divided into two. If the received message is a register message, the network controller 10 A process related to registration of the communication terminal in the network is performed. If the received message is a message message, the network control device 10 performs a process of connecting the communication with the communication terminal 40 of the designated destination.

First, a case where the received message is a register message will be described. The message analysis unit 14 extracts header and body information of the register message (S84). Here, the URI of the communication terminal 40 and the wireless 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 registers or unregisters 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 information of the header of the invite message (S88) and inputs the information to the routing control unit 24. Here, the information of the URI of the source and destination communication terminals 40 of the invite message is extracted.

[0118] Upon receiving the information from the message analysis unit 14, the routing control unit 24 acquires the information of the communication terminal 40 on the receiving side from the terminal location information storage unit 32 (S90). Then, based on the terminal location information 32, the routing control unit 24 also selects a network to be used for communication based on the network power to which the communication terminal 40 on the receiving side is connected (S92). Then, the network control unit creates and transmits a register message to be transmitted by the selected network (S94).

[0119] The communication terminal 40 and the network control device 10 according to the second embodiment have been described above.

[0120] The communication terminal 40 of the second embodiment detects the strength of radio waves received through the network, compares the detected radio wave strength with a predetermined boundary value, and connects to the network. Is determined. The boundary value stores information on the signal strength required to maintain communication, and if the signal strength is greater than the boundary value, the connection to the network is registered. It can be carried out.

Industrial applicability

[0121] As described above, the present invention provides a network for communication performed in a connection established by a connection request, based on network selection information registered in the communication terminal of the called side. If a network that meets the needs of the user on the receiving side can be selected as the network on the receiving side because the network is selected, it has an excellent effect and can be connected to a plurality of networks using different communication methods. It is useful as a network control device for controlling connection to communication terminals.

Claims

The scope of the claims

[1] A network control device for controlling connection to a communication terminal connectable to a plurality of networks having different communication methods,

Network selection information storage means storing the registered information of the communication terminal to select one of the plurality of networks;

A connection request receiving unit for receiving a connection request for communication addressed to the communication terminal; and a network for communication performed by a connection established by the connection request received by the connection request receiving unit, stored in the network selection information storage unit. Network selection means for selecting based on the received information,

A connection request transmitting unit that transmits the connection request to the communication terminal through the network selected by the network selecting unit;

A network control device comprising:

[2] 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,

The network selection means selects a network based on information on the intensity of the radio wave stored in the network selection information storage means;

The network control device according to claim 1, wherein:

[3] The network selection information storage means stores information on radio field intensity required for communication for each communication type,

The network selecting means determines a communication type to be performed in a connection established by the connection request received by the connection request receiving means, and determines a radio wave intensity required for communication of the determined type and a radio wave intensity of the communication terminal. Network based on information about

3. The network control device according to claim 2, wherein:

[4] The network selection information storage means stores information related to network security required for communication,

The network selection unit selects a network based on information on security stored in the network selection information storage unit; The network control device according to claim 1, wherein:

[5] The network selection information storage means stores the information related to the security in association with the information related to the terminal that transmitted the connection request,

The network selection unit extracts information on a connection request source received by the connection request reception unit and information on a source terminal, and stores information on security necessary for communication with the transmission source terminal in the network selection information storage unit. Based on the extracted security information, select the network!

5. The network control device according to claim 4, wherein:

[6] The network selection information storage means stores the information on the security for each communication type,

The network selection unit determines a type of communication performed in a connection established by the connection request received by the connection request reception unit, and extracts information related to security necessary for communication of the communication type from the network selection information storage unit. Select networks based on extracted security information,

5. The network control device according to claim 4, wherein:

[7] The network selection information storage means stores information on a network communication speed required for communication,

The network selection means selects a network based on the communication speed information stored in the network selection information storage means;

The network control device according to claim 1, wherein:

[8] The network selection information storage means stores information related to the communication speed in association with information related to a terminal that has transmitted a connection request,

The network selection unit extracts information on a connection request source terminal received by the connection request reception unit and information on a communication speed required for communication with the transmission source terminal. Based on the information about the extracted communication speed,

8. The network control device according to claim 7, wherein:

[9] The network selection information storage means stores information on the communication speed for each communication type. Information,

The network selection unit determines a communication type to be performed in a connection established by the connection request received by the connection request reception unit, and stores information on a communication speed required for communication of the communication type from the network selection information storage unit. Extracting and selecting a network based on the extracted information on the communication speed,

8. The network control device according to claim 7, wherein:

[10] A network control device for controlling connection to a communication terminal connectable to a plurality of networks having different communication methods,

Radio wave intensity information receiving means for receiving, from the communication terminal, radio wave intensity information relating to radio wave intensity received by the communication terminal through the plurality of networks;

Registration processing means for registering or canceling the registration of the communication terminal as a terminal connected to the one network, based on the radio wave intensity information received by the radio wave intensity information receiving means;

A network control device, comprising: a connection request transmitting unit that transmits a connection request addressed to the communication terminal via a network selected from the networks registered by the registration processing unit.

[11] The registration processing unit registers the communication terminal based on the radio wave intensity information received by the radio wave intensity information receiving unit when the radio wave intensity of the communication terminal exceeds a predetermined threshold value. Canceling the registration of the communication terminal when the radio field intensity of the communication terminal is equal to or less than the threshold,

11. The network control device according to claim 10, wherein:

[12] The radio wave intensity information receiving unit receives a SIP message including radio wave intensity information, and the registration processing unit extracts body force radio wave intensity information of the SIP message received by the radio wave intensity information receiving unit,

11. The network control device according to claim 10, wherein:

[13] A communication terminal connected to a network control device that selects a network to be used for an incoming call to a power communication terminal among a plurality of networks having different communication methods based on the radio wave intensity of the communication terminal, Means for detecting the strength of radio waves received through a plurality of networks using different communication methods;

A radio wave intensity information transmitting unit that transmits information about the radio wave intensity to the network control device when the radio wave intensity detected by the radio wave intensity detecting unit changes beyond a predetermined threshold;

A communication terminal comprising:

[14] a radio wave intensity detecting means for detecting a radio wave intensity received through a plurality of networks having different communication methods,

Determining means for determining whether to use the one network based on the strength of the radio wave detected by the radio wave strength detecting means;

Network control for controlling connection to the network based on a result of the determination by the determination means, and for registering the communication terminal as a terminal connected to the network or canceling the registration. Request message sending means to be sent to the device;

A communication terminal comprising:

[15] The determination means determines that the one network is to be used when the radio field intensity detected by the radio field intensity detection section exceeds a predetermined threshold, and the radio field intensity detected by the radio field intensity detection section is used. Is determined not to use the one network when is less than or equal to the threshold,

15. The communication terminal according to claim 14, wherein:

[16] The request message transmitting means transmits the request message when a result of the determination by the determining means as to whether or not the first network is to be used has changed,

15. The communication terminal according to claim 14, wherein:

[17] The request message transmitting unit transmits a SIP message including information on whether to register the communication terminal with the network or to cancel the registration.

15. The communication terminal according to claim 14, wherein:

[18] A communication connection method for a communication terminal connectable to a plurality of networks having different communication methods, A connection request receiving step in which a network control device that controls the communication terminal receives a connection request for communication addressed to the communication terminal;

The network control device, in the connection request receiving step, sets a network for communication performed by a connection established by the connection request received in one of the plurality of networks registered from the communication terminal. Selecting a network based on the information for selecting one;

A connection request transmitting step of transmitting the connection request to the communication terminal through the network selected in the network control step;

A communication connection method, comprising:

[19] A method of registering a communication terminal connectable to a plurality of networks having different communication methods as a terminal connected to the network,

A network control device that controls the communication terminal, radio wave intensity information related to radio wave intensity received by the communication terminal through the plurality of networks, radio wave intensity information receiving step of receiving from the communication terminal,

A registration processing step of registering the communication terminal as a terminal connected to the one network or canceling the registration based on the received radio wave intensity information in the radio wave intensity information receiving step;

With

A method of registering connection to a network, wherein the network registered in the registration processing step is a candidate for a network used for transmitting a connection request addressed to the communication terminal.

[20] a radio wave intensity detecting step of detecting a radio wave intensity received by the communication terminal through a plurality of networks using different communication methods;

A determination step in which the communication terminal determines, based on the intensity of the radio wave detected in the radio wave intensity detection step, whether or not the communication terminal uses the one network;

A request message for registering the communication terminal as a terminal connected to the network or canceling the registration based on a result of the determination in the determination step. Transmitting a request message to a network control device that controls connection to the network;

A method for registering connection to a network, comprising: