JP2008244853A - Communication control apparatus and protocol converting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a mobile communication terminal having no IMS (IP Multimedia Subsystems) function to access a core network of the IMS without establishing a session that the mobile communication terminal transmits/receives an IP packet to/from the network. <P>SOLUTION: When a communication is generated by a protocol used for an access network 300 or an SIP used for an IMS core network 400, in a communication control apparatus 100, a signal analyzing section 120 identifies which kind of signal is received by each protocol. A protocol converting section 121 then can convert that signal into a signal of the same function in other protocols. When a Setup signal indicating a transmission signal being used for a 3G communication protocol is received, for example, the Setup signal can be converted into an INVITE signal showing a transmission signal in the SIP. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a communication control apparatus and a protocol conversion method for converting a communication protocol used in a mobile phone or the like into a communication protocol that can be used in an IMS core network.

In recent years, communication networks using IP (Internet Protocol) technology have been considered, and a standard called IMS (IP Multimedia Subsystem) has been considered in 3GPP. The contents of this standard are described in Non-Patent Document 1, for example.
3GPP TS 23.228 V7.6.0 (2006-12) 3rd GenerationPartnership Project; Technical Specification Group Services and SystemAspects; IP Multimedia Subsystem (IMS); Stage 2 (Release 7), [Search February 23, 2007], Internet <URL : http: //www.3gpp.org/ftp/Specs/2006-12/Rel-7/23_series/23228-760.zip>

  When a mobile communication terminal tries to connect to the IMS core network, the mobile communication terminal has a function of connecting to the IMS core network in the first place, and the mobile communication terminal is a P- It was necessary to connect to a CSCF (Proxy-Call Session Control Function). Further, the mobile communication terminal needs to be connected to the P-CSCF via a network (IP-CAN (IP-Connectivity Access Network)) that can be connected by IP.

  For example, the function for connecting to the IMS core network, that is, the access network used by the third generation (3G) mobile phone having the IMS function is not an IP-CAN. could not. Therefore, in order to use the IMS core network, a session in which the mobile communication terminal can transmit and receive IP packets to and from the network is established using conventional techniques such as unrestricted digital connection and packet connection, and P is transmitted by transmitting and receiving data on the session. -Needed access to CSCF.

  However, a mobile communication terminal that does not have an IMS function cannot perform the above-described processing, and thus cannot connect to the IMS core network via an access network in the 3G communication network.

  Accordingly, the present invention provides a communication control apparatus and protocol that allows a mobile communication terminal to access an IMS core network from a mobile communication terminal that does not have an IMS function without establishing a session for the mobile communication terminal to transmit and receive IP packets to and from the network. An object is to provide a conversion method.

  The communication control device of the present invention executes first communication means for communication connection with a communication terminal capable of executing communication using a first communication protocol usable in a public mobile communication network, and communication using a second communication protocol. A second communication means for communication connection with an IMS (IP Multimedia Subsystems) core network constructed so that the first communication means or the communication by the second communication means occurs, the first communication Conversion means for mutually converting the first communication protocol executed by the means and the second communication protocol executed by the second communication means.

  Further, the protocol conversion method of the present invention includes a first communication step for communication connection with a communication terminal capable of executing communication using a first communication protocol that can be used in a public mobile communication network, and communication using a second communication protocol. When communication occurs in a second communication step for communication connection with an IMS (IP Multimedia Subsystems) core network constructed so as to be able to execute the first communication step or the second communication step, the second communication step occurs. A conversion step for converting between the first communication protocol executed in one communication step and the second communication protocol executed in the second communication step.

  According to the present invention, when communication using the first communication protocol or the second communication protocol occurs, the first communication protocol and the second communication protocol can be mutually converted. Therefore, for example, when a new communication protocol used in the IMS core network and a communication protocol used in an existing public mobile communication coexist, the communication is made to a communication terminal that can use only any communication protocol. It is possible to enable communication with another communication terminal that can use only a communication protocol that cannot be used in the terminal.

  When the location registration request is made from the communication terminal, the conversion means of the communication control apparatus of the present invention sends the location registration request by the first communication protocol to the second communication protocol after the authentication process is performed. The second communication means converts the converted location registration request to a location registration server installed in the IMS core network constructed so as to be able to execute communication using the second communication protocol. It is characterized by transmitting.

  According to the present invention, when a location registration request is made from a communication terminal, after the authentication process is performed, the location registration request according to the first communication protocol is converted into a location registration request according to the second communication protocol, and the IMS is performed. It can be transmitted to a location registration server installed in the core network. Therefore, even if a communication terminal that cannot directly communicate with the IMS core network is located in an area where only the IMS core network communication service is provided, location registration can be performed in the IMS core network. .

  In addition, when a transmission request is made from the communication terminal, the conversion means of the communication control device of the present invention establishes a communication path, and then transmits the transmission request for the first communication protocol to the transmission of the second communication protocol. The request is converted into a request, and the second communication means transmits the converted call request to the IMS core network.

  According to the present invention, when a transmission request is made from a communication terminal, after establishing a communication path, the transmission request of the first communication protocol is converted into the transmission request of the second communication protocol, and the converted transmission request is Even if the communication terminal can transmit to the IMS core network and cannot directly communicate with the IMS core network, it can communicate with other communication terminals that can directly communicate with the IMS core network only. To make outgoing calls.

  In addition, since the protocol conversion process is performed after the communication path is established with the communication terminal, communication can be reliably executed after the protocol conversion process, and the communication path can be established even though the protocol conversion process has been performed. The communication is never interrupted.

  In addition, when the conversion request of the communication control apparatus according to the present invention performs a paging process on the communication terminal that is the destination when an incoming call request is made via the IMS core network, the conversion unit of the second communication protocol The incoming request is converted into an incoming request of the second communication protocol, and the first communication means transmits the converted incoming request to the communication terminal.

  According to the present invention, when an incoming call request is made from the IMS core network, an incoming request of the second communication protocol is converted into an incoming request of the second communication protocol after establishing a communication path with the communication terminal. The converted transmission request can be transmitted to the communication terminal. Thereby, even if it is a communication terminal which cannot communicate directly with an IMS core network, the incoming process from the other communication terminal which can communicate directly only with an IMS core network can be performed.

  Further, since the protocol conversion process is performed after the paging process for the communication terminal is performed, the communication can be surely performed after the protocol conversion process, and the paging process for the communication terminal is performed although the protocol conversion process is performed. Communication cannot be interrupted.

  In the case where a new communication protocol used in an IMS core network and a communication protocol used in an existing public mobile communication coexist, the present invention can be applied to a communication terminal that can use only any communication protocol. It is possible to enable communication with another communication terminal that can use only a communication protocol that cannot be used in the communication terminal.

  The present invention can be readily understood by considering the following detailed description with reference to the accompanying drawings shown for the embodiments. Subsequently, embodiments of the present invention will be described with reference to the accompanying drawings. Where possible, the same parts are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a system configuration diagram showing a communication system using a communication control apparatus 100 (IWF (Inter-Working Function)) in the present embodiment.

  The communication control apparatus 100 is connected to the access network 300 and the IMS core network 400, and communicates between the access network 300 and the IMS core network 400 for accessing a 3G communication network such as a public mobile communication network. This is a device that performs protocol conversion processing. In this embodiment, it is a device that can mutually convert 3G communication protocol and SIP (Session Initiation Protocol). As shown in FIG. 1, the communication control apparatus 100 can be connected for communication from a mobile device 200 via an access network 300, and communication signals and the like from the mobile device 200 are transmitted to the IMS core network 400 in the communication control device 100. Is converted into a usable communication signal. Here, the access network 300 is a network for connecting to a 3G communication network such as a base station or a radio network controller. Further, the communication control apparatus 100 can communicate with an HLR (Home Location Register) 600, perform location registration with the HLR 600 in response to a request from the mobile device 200, or acquire various types of information such as authentication information. .

  The IMS core network 400 is connected to an access network 500 (IP-CAN (IP-CAN connectivity access network)) for performing IP connection. The access network 500 is a network capable of performing IP communication such as GPRS (General Packet Radio Service), ADSL (Asymmetric Digital Subscriber Line), or WLAN (Wireless LAN). In the example shown in FIG. Are connected for communication. The mobile device 201 has a function capable of executing communication using the IMS core network. Further, the IMS core network includes an HSS (Home Subscriber Server) 700, and Registration for location registration can be performed from the mobile device 200 or 201.

  In such a communication system, when attempting to establish a communication connection with the mobile device 201, the mobile device 200 first establishes a communication connection with the communication control apparatus 100 via the access network 300. The communication control device 100 converts a communication signal used in a 3G communication network or the like, that is, a communication signal based on the first protocol, into a communication signal based on a second protocol that can be used in the IMS core network, The converted communication signal is transmitted to the mobile device 201 via the access network 500. Further, the communication control apparatus 100 converts a communication signal that can be used in the IMS core network into a communication signal used in the 3G communication network, and converts the communication signal converted into the mobile device 200 connected to the access network 300. Send.

  Next, a detailed configuration of the communication control apparatus 100 will be described. FIG. 2 is a block configuration diagram showing the configuration of the communication control apparatus 100. As shown in FIG. 2, the communication control apparatus 100 includes a 3G processing unit for performing communication processing for a 3G communication network such as a public mobile communication network, and an IMS for performing communication processing for the IMS core network. The 3G processing unit includes a 3G control signal receiving unit 101, a 3G authentication processing unit 102, a 3G confidential processing unit 103, a 3G-RAB establishment processing unit 104, and a 3G-Paging processing unit 105. The 3G control signal transmitting unit 106, the 3G user information holding unit 107, the 3G data receiving unit 108, and the 3G data transmitting unit 109 are configured. The IMS processing unit includes an IMS signal receiving unit 110, an IMS incoming processing unit 111, an IMS-Registration processing unit 112, an IMS transmission processing unit 113, an IMS user information holding unit 114, an IMS data transmission unit 115, and an IMS data receiving unit. 116 is comprised. The conversion unit is arranged between the 3G processing unit and the IMS processing unit, and performs conversion processing in each protocol in the 3G processing unit and the IMS processing unit. The conversion unit includes a signal analysis unit 120, a protocol conversion unit 121, a data association unit 123, and a data conversion unit 124. Each configuration will be described below.

  The 3G control signal receiving unit 101 is a part that receives a control signal from the access network 300 in the 3G communication network. The 3G authentication processing unit 102 is a part that performs authentication processing for communication connection. The 3G concealment processing unit 103 is a part that instructs to perform transmission / reception between the access network 300 and the mobile device 200. By this instruction, the wireless section between the mobile device 200 and the access network 300 is transmitted / received with encrypted data. The 3G-RAB establishment processing unit 104 is a part that establishes a voice call path for performing a call between the mobile device 200 and the mobile device 201.

  The 3G-Paging processing unit 105 is a part that performs paging processing, that is, call processing, on the mobile device. The 3G control signal transmission unit 106 is a part that transmits a control signal to the mobile device that has undergone the paging process. Paging is a process of calling a mobile terminal by transmitting a request to a base station in which the mobile terminal to be called is located.

  The 3G user information holding unit 107 is a part that holds user information in the 3G network, and is a part that stores, for example, a telephone number, a temporary ID, and an IMUI (International Mobile Station Identity). The telephone number is a telephone number of a terminal such as the mobile device 200, the temporary ID is an ID temporarily assigned during communication, and the IMUI is a solid identification number assigned to a SIM card attached to the mobile device. is there.

  The 3G data reception unit 108 is a part that receives data or voice data from the mobile device 200 via the access network 300. The 3G data transmission unit 109 is converted by the data conversion unit 124 with respect to the access network 300 This is the part that transmits data or audio data.

  The IMS signal receiving unit 110 is a part that receives a control signal via the IMS core network 400, and the IMS incoming signal processing unit 111 is a part that performs incoming processing when receiving an incoming signal among the control signals.

  The IMS-Registration processing unit 112 receives a registration request in the SIP used in the IMS core network, which is converted from the location registration request in the 3G communication protocol used in the 3G communication network by the protocol conversion unit 121, and the Registration request This is a part for transmitting a request to the HSS 700.

  The IMS transmission processing unit 113 is a part that transmits to a communication partner connected to the IMS core network based on a transmission signal transmitted via the 3G communication network. In addition, the IMS transmission processing unit 113 is a part that transmits various control signals to the mobile device 201 in the IMS core network.

  The IMS user information holding unit 114 is a part that holds user information in the IMS core network 400. For example, a URI (Uniform Resource Identifier) that uniquely identifies the mobile device 201, a telephone number, and address information of a server that performs call control. This is the part that is stored in association with each other.

  The IMS data transmission unit 115 is a part that transmits data conforming to the IMS core network converted by the data conversion unit 124 to the IMS core network 400, and the IMS data reception unit 116 transmits data transmitted from the IMS core network 400 This is the part that receives

  The signal analysis unit 120 includes various signals received by the IMS signal reception unit 110, the IMS incoming processing unit 111, the 3G control signal reception unit 101, the 3G authentication processing unit 102, the 3G confidential processing unit 103, and the 3G-RAB establishment processing unit 104. It is the part that identifies the signal. The signal analysis unit 120 outputs the identified result to the protocol conversion unit 121. In the present embodiment, the signal analysis unit 120 identifies at least a location registration request from the mobile device 200, a Setup signal that is a transmission signal, a CallConfirmed signal, an Alerting signal, and a Connect signal. In addition, you may make it identify the signal according to a communication procedure.

  Further, the signal analyzing unit 120 identifies that at least the Registration response signal is received from the HSS 700 and that the Session Progress signal, Ringing signal, OK signal, and INVITE signal are received from the mobile device 201. In addition, you may make it identify the signal according to a communication procedure.

  The protocol conversion unit 121 receives the signal identification result output from the signal analysis unit 120, determines which signal to convert to which signal based on the identification result, and performs conversion processing according to the determination It is. That is, when receiving a signal in the 3G communication protocol from the mobile device 200, the protocol converter 121 converts it into a signal having the same function in SIP according to the function of the signal. For example, when a location registration request is identified by the signal analysis unit 120, the location registration request is converted into a Registration signal according to the function of the signal. When the Setup signal, which is a transmission signal, is identified, the signal is converted into an INVITE signal. When the CallConfirmed signal is identified, the signal is converted into a SessionProgress signal. When the alerting signal is identified, the alerting signal is converted into a ringing signal. When the Connect signal is identified, the signal is converted into an OK signal.

  Contrary to the above, when receiving a SIP signal from the mobile device 201, the protocol converter 121 converts the signal into a signal having the same function in the 3G communication protocol according to the function of the signal. For example, when the registration response signal from the HSS 700 is identified, the protocol conversion unit 121 converts the registration response signal into a location registration response signal. When the ringing signal is identified, the protocol conversion unit 121 converts the signal into an alerting signal, and OK. When the signal is identified, the signal is converted into a Connect signal. When the INVITE signal is identified, the signal is converted into a Setup signal.

  The data association unit 123 performs a conversion process of a telephone number as a destination according to the user information held by the 3G user information holding unit 107 and the user information held by the IMS user information holding unit 114 It is. For example, the data association unit 123 converts the destination telephone number transmitted from the mobile device 200 into a URI of the other party according to a predetermined rule so as to be able to perform outgoing call processing, and retains IMS user information. According to the information stored in unit 114, the caller telephone number transmitted from mobile device 200 is converted into a SIP URI. Using the data thus converted, the protocol converter 121 and the data converter 124 can transmit a control signal or data to the destination converted by the 3G data transmitter 109 and the IMS data transmitter 115. Thus, the data conversion is performed. Conversely, the SIP URI transmitted from the mobile device 201 may be extracted according to the information stored in the IMS user information holding unit 114, and the extracted telephone number may be the destination.

  The data converter 124 is a part that converts data such as voice data, converts the voice data received by the IMS data receiver 116 into a data format that conforms to the 3G communication protocol, and the 3G data receiver 108 This is a part that converts received voice data into a data format that conforms to SIP (protocol used in the IMS core network). The converted voice data is transmitted by the IMS data transmission unit 115 or the 3G data transmission unit 109, respectively.

  As shown in FIG. 3, the communication control device 100 configured in this way physically includes a CPU 11, a RAM 12 and a ROM 13 that are main storage devices, an auxiliary storage device 15 such as a hard disk, and a keyboard and a mouse that are input devices. The computer system includes an input device 16 such as a display, an output device 17 such as a display, and a communication module 14 that is a data transmission / reception device such as a network card. Each function described in FIG. 2 has a communication module 14, an input device 16, and an output device 17 under the control of the CPU 11 by reading predetermined computer software on the hardware such as the CPU 11 and the RAM 12 shown in FIG. 3. This is realized by reading and writing data in the RAM 12 and the auxiliary storage device 15.

  An operation of the communication system including the communication control apparatus 100 configured as described above will be described. 4 to 6 are sequence diagrams illustrating the operation of the communication control apparatus 100 according to the present embodiment. This will be sequentially described below. FIG. 4 is a sequence diagram showing an operation of the communication control apparatus 100 when the mobile device 200 performs location registration in the IMS core network.

  First, when the mobile device 200 is turned on or a predetermined time has elapsed, a request for location registration is transmitted from the mobile device 200 to the communication control apparatus 100 via the access network 300 (S101). In the communication control apparatus 100, the 3G authentication processing unit 102 is activated (S102), and authentication information is acquired from the HLR 600 by the 3G authentication processing unit 102 (S103). Then, authentication processing is performed by the 3G authentication processing unit 102 (S104).

  After the authentication process, the 3G concealment processing unit 103 is activated (S105), the concealment process is performed by the 3G concealment processing unit 103, and the concealment process is instructed to the access network 300 (S106).

  Thereafter, based on the signal analysis by the signal analysis unit 120, the protocol conversion unit 121 performs protocol conversion processing. Here, the location registration request by the 3G communication protocol is identified by the signal analysis unit 120, and the location conversion request is converted by the protocol conversion unit 121 into a Registration request indicating the location registration request by SIP (S107). Then, the IMS-Registration processing unit 112 transmits a Registration request to the IMS core network 400 (S108), and registration processing by SIP is performed (S109). Here, location registration is performed for the HSS 700 that performs location management in the IMS core network 400.

  In the IMS core network 400, after completion of the registration process, a registration response is transmitted to the communication control apparatus 100 (S110). When the registration response is received by the registration processing unit 112 in the communication control apparatus 100, the registration response is converted into the location registration response of the 3G communication protocol by the protocol conversion unit 121 (S111), and the location registration response is converted to the 3G control signal transmission unit. 106 is transmitted to the mobile device 200 (S112).

  By such processing, when the mobile device 200 that cannot communicate with the IMS core network 400, that is, the mobile device 200 that can use only the 3G communication protocol is provided with only the communication service by the IMS core network, the 3G Location registration can be performed for the ISM communication network using the communication protocol and using the access network of the 3G communication network.

  Next, the operation of the entire communication system when the mobile device 200 performs a calling process on the mobile device 201 configured to be connectable to the IMS core network will be described. FIG. 5 is a sequence diagram showing the operation of communication control apparatus 100 at that time.

  First, a Setup signal indicating a transmission process is transmitted to the communication control apparatus 100 in the mobile device 200 (S201). Thereafter, an authentication process and a concealment process are performed between the mobile device 200 and the communication control apparatus 100 (S202). The detailed process is the same as the process of S102 to S106 in FIG.

  Next, a CallProceeding signal, which is a response to the calling process, is transmitted from the communication control device 100, and RAB establishment processing, which is a voice call path establishment, is performed between the mobile device 200 and the communication control device 100. RAB establishment processing is performed by the RAB establishment processing unit 104 (S204).

  After the RAB establishment process, the communication control apparatus 100 performs a protocol conversion process for the outgoing call process in the conversion unit. Here, the setup signal is recognized by the signal analysis unit 120, and after the RAB establishment process, the protocol conversion unit 121 converts the setup signal into an INVITE signal in SIP (S205). Then, the converted INVITE signal is transmitted to the mobile device 201 by the IMS transmission processing unit 113 (S206). After that, a SessionProgress signal indicating a call connection state is transmitted from the IMS core network 400 to the communication control apparatus 100 as a response to the INVITE signal (S207), and Ringing indicating that the call is being performed. A signal is transmitted to the communication control apparatus 100 (S208). In this embodiment, the SessionProgress signal and Ringing signal are transmitted from the mobile device 201. For example, when the destination is a terminal connected to the PSTN or 3G communication network, the IMS core A gateway device installed between the network and the PSTN or 3G communication network transmits a SessionProgress signal and a Ringing signal.

  In the communication control apparatus 100, when the Ringing signal is received by the IMS signal receiving unit 110, the signal is identified by the signal analyzing unit 120, and the protocol converting process is performed by the protocol converting unit 121 based on the identification result. Here, the Ring signal in SIP is converted into the Alerting signal in 3G communication protocol by the protocol converter 121 (S209). Then, the 3G control signal transmission unit 106 transmits an alerting signal to the mobile device 200 (S210).

  In mobile device 201, when an off-hook process is performed by a user operation and an OK signal in SIP is transmitted, in communication control device 100, an OK signal is received by IMS signal receiving unit 110, and an OK signal is received by signal analysis unit 120. The SIP OK signal is converted into a Connect signal in the 3G communication protocol by the protocol converter 121 (S212). In the communication control device 100, the 3G control signal transmission unit 106 transmits a Connect signal to the mobile device 200 (S213). Then, a ConnectAck signal as a response is transmitted from the mobile device 200 and received by the 3G control signal receiving unit 101 in the communication control apparatus 100 (S214).

  Through such processing, the mobile device 200 that cannot communicate directly with the IMS core network 400 transmits to the mobile device 201 belonging to the IMS core network 400.

  Next, an operation when the mobile device 200 receives an incoming call from the mobile device 201 belonging to the IMS core network 400 via the communication control apparatus 100 will be described. FIG. 6 is a sequence diagram showing an operation of the communication control apparatus 100 that performs incoming processing from the mobile device 201 belonging to the IMS core network 400.

  An INVITE signal that is an incoming signal from the mobile device 201 is received by the IMS signal receiving unit 110 in the communication control apparatus 100 via the IMS core network 400. When the INVITE signal is received, incoming call processing is performed by the IMS incoming call processing unit 111 (S301). Here, prior to the incoming call processing, when the INVITE signal is received, the 3G-Paging processing unit 105 performs the Paging processing (S302), and the authentication processing and the confidential processing are the 3G authentication processing unit 102 and the 3G confidential processing unit, respectively. 103 (S303).

  Then, the signal analysis unit 120 analyzes that the INVITE signal has been received, and the protocol conversion unit 121 converts the INVITE signal into a Setup signal that is a transmission signal of the 3G communication protocol (S304). The converted Setup signal is transmitted from the communication control device 100 to the mobile device 200 (S305). In the mobile device 200, when the Setup signal is received, a CallConfirmed signal that is a response signal is transmitted. In the communication control apparatus 100, the 3G control signal receiving unit 101 receives the CallConfirmed signal (S306).

  In the communication control apparatus 100, it is identified that the signal received by the signal analysis unit 120 is a CallConfirmed signal, and the CalLConfirmed signal is converted into a SessionProgress signal by the protocol conversion unit 121 (S307). The converted SessionProgress signal is transmitted to the mobile device 201 by the IMS transmission processing unit 113 (S308).

  Next, in the communication control device 100, the 3G-RAB establishment processing unit 104 performs RAB establishment processing between the communication control device 100 and the mobile device 200 (S309). When the RAB establishment process is performed, an alerting signal is transmitted from the mobile device 200, and the communication control apparatus 100 receives the alerting signal (S310). In the communication control apparatus 100, the signal analyzing unit 120 identifies that the signal is an alerting signal, and the protocol converting unit 121 converts the alerting signal into a ringing signal based on the identification result (S311). After the conversion, a Ringing signal is transmitted to the mobile device 201 by the IMS transmission processing unit 113 (S312).

  In the mobile device 200, when an off-hook process is performed by the user operation, a Connect signal is transmitted, and the communication control device 100 receives the transmitted Connect signal (S313). In the communication control apparatus 100, the signal analysis unit 120 recognizes that the Connect signal has been received, and the Connect signal is converted into an OK signal by the protocol conversion unit 121 based on the identification result (S314). Thereafter, the IMS transmission processing unit 113 transmits the converted OK signal (S315), and the 3A control signal transmission unit 106 transmits the ConnectAck signal (S316).

  By such processing, the mobile device 200 that cannot communicate directly with the IMS core network 400 can perform incoming processing from the mobile device 201 that can communicate directly with the IMS core network 400.

  Next, operational effects of the communication control apparatus 100 of the present embodiment will be described. The communication control apparatus 100 according to the present embodiment uses a first communication protocol such as a 3G communication protocol used in a 3G communication network (here, the access network 300) or a second communication such as SIP used in the IMS core network 400. When communication by the protocol occurs, the signal analysis unit 120 identifies what signal is received in the first protocol or the second protocol. Then, the protocol conversion unit 121 can convert the signal into a signal having the same function in another protocol. For example, when a Setup signal indicating a transmission signal used in a 3G communication protocol is received, the Setup signal can be converted into an INVITE signal indicating a transmission signal in SIP, The communication protocol and the second communication protocol can be converted into each other. Therefore, for example, when a new communication protocol such as SIP used in the IMS core network 400 and a communication protocol used in the existing public mobile communication coexist, the mobile device that can be used only in any communication protocol 200 or 201 can be communicated with a mobile device 201 that is another communication terminal that can use only a communication protocol that cannot be used by the mobile device 200.

  In addition, when a location registration request is made from the mobile device 200, the communication control apparatus 100 performs a location registration request based on the first communication protocol on the second communication after the authentication processing is performed in the 3G authentication processing unit 102 or the like. It can be converted into a Registration request signal that is a location registration request in the protocol and transmitted to the HSS 700 that is a location registration server installed in the IMS core network 400. Therefore, even if the mobile device 200 that cannot directly communicate with the IMS core network 400 is located in an area where only the communication service by the IMS core network 400 is provided, the mobile device 200 is connected to the HSS 700 in the IMS core network 400. Position registration.

  Further, when a transmission request is made from the mobile device 200, the communication control apparatus 100 establishes a communication signal such as a voice call by the RAB establishment processing unit 104, and then sends a Setup signal that is a transmission request for the first communication protocol. 2 is converted into an INVITE signal that is a transmission request of the communication protocol 2, and the converted INVITE signal can be transmitted to the IMS core network (that is, the mobile device 201). Therefore, the mobile device 200 that cannot directly communicate with the IMS core network 400 performs a calling process on the mobile device 201 that is another communication terminal that can directly communicate only with the IMS core network 400. be able to.

  In addition, since the communication control apparatus 100 performs a protocol conversion process by the protocol conversion unit 121 after a communication path such as a voice call is established with the mobile device 200, the communication control apparatus 100 reliably performs communication after the protocol conversion process. Even though the protocol conversion process is performed, the communication path cannot be established and communication is not interrupted.

  Further, when an incoming call request is made from the IMS core network 400 (for example, the mobile device 201), the communication control apparatus 100 establishes a communication path with the mobile device 200 and then receives an incoming SIP signal as the first communication protocol. The INVITE signal indicating the request can be converted into a Setup signal indicating the incoming request used in the 3G communication network which is the first communication protocol. Then, the communication control apparatus 100 can transmit the converted Setup signal toward the mobile device 200. Accordingly, the mobile device 200 that cannot directly communicate with the IMS core network 400 can perform incoming processing from the mobile device 201 that can directly communicate with the IMS core network 400 only.

  In addition, since the protocol conversion process is performed after the paging process for the mobile device 200 is performed, communication can be reliably performed after the protocol conversion process by the protocol conversion unit 121, and the protocol conversion process is performed. The paging process for the mobile device 200 cannot be performed, and communication is not interrupted.

1 is a system configuration diagram showing a communication system using a communication control device 100 (IWF (Inter-Working Function)) in the present embodiment. 2 is a block configuration diagram showing a configuration of a communication control apparatus 100. FIG. 2 is a block diagram showing a hardware configuration of a communication control apparatus 100. FIG. It is a sequence diagram which shows operation | movement of the communication control apparatus 100 when the mobile device 200 performs location registration in an IMS core network. FIG. 10 is a sequence diagram illustrating an operation of the communication control apparatus 100 when the mobile device 200 performs a calling process on the mobile device 201. It is a sequence diagram which shows operation | movement of the communication control apparatus 100 which performs the incoming call process from the mobile apparatus 201 which belongs to an IMS core network.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Communication control apparatus, 101 ... 3G control signal receiving part, 102 ... 3G authentication process part, 103 ... 3G secrecy process part, 104 ... 3G establishment process part, 105 ... 3G-Paging process part, 106 ... 3G control signal transmission part 107 ... 3G user information holding unit, 108 ... 3G data receiving unit, 109 ... 3G data transmitting unit, 110 ... IMS signal receiving unit, 111 ... IMS incoming processing unit, 112 ... IMS-Registration processing unit, 113 ... IMS transmission processing 114, IMS user information holding unit, 115 ... IMS data transmission unit, 116 ... IMS data reception unit, 120 ... Signal analysis unit, 121 ... Protocol conversion unit, 123 ... Data correspondence unit, 124 ... Data conversion unit, 200 ... mobile station 201 ... mobile station 300 ... access network 400 ... IMS core network 500 ... access network , 600 ... HLR, 700 ... HSS.

Claims (5)

First communication means for communication connection with a communication terminal capable of executing communication using a first communication protocol that can be used in a public mobile communication network;
Second communication means for communicating with an IMS (IP Multimedia Subsystems) core network constructed so as to be able to execute communication according to a second communication protocol;
When communication by the first communication means or the second communication means occurs, the first communication protocol executed by the first communication means and the second communication protocol executed by the second communication means are mutually A communication control device comprising: conversion means for converting into When a location registration request is made from the communication terminal, the converting means converts the location registration request based on the first communication protocol into a location registration request based on the second communication protocol after authentication processing is performed. ,
The second communication means transmits the converted location registration request to a location registration server installed in an IMS core network constructed so as to be able to execute communication using the second communication protocol. Item 4. The communication control device according to Item 1. When a transmission request is made from the communication terminal, the converting means converts a transmission request of the first communication protocol into a transmission request of the second communication protocol after establishing a communication path,
The communication control apparatus according to claim 1, wherein the second communication unit transmits the converted call request to the IMS core network. When an incoming call request is made via the IMS core network, the conversion means performs a paging process on the communication terminal that is the incoming call destination, and then sends the incoming call request of the second communication protocol to the second communication protocol. To incoming requests for
The communication control apparatus according to claim 1, wherein the first communication unit transmits the converted incoming request to the communication terminal. A first communication step of communicating with a communication terminal capable of executing communication according to a first communication protocol usable in a public mobile communication network;
A second communication step of communicatively connecting to an IMS (IP Multimedia Subsystems) core network constructed so as to be able to execute communication according to a second communication protocol;
When communication in the first communication step or the second communication step occurs, the first communication protocol executed in the first communication step and the second communication protocol executed in the second communication step are mutually A protocol conversion method comprising: a conversion step of converting into a protocol.

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