Telephone number investigation device, investigation method, investigation program

Abstract

To efficiently determine the usage status of a telephone number to be investigated. [Solution] A telephone number investigation device (10) is connected to a plurality of IMS terminals (50) connected to a terminating mobile IMS network (30) via an originating fixed IMS network (20), adds SDP parameters to an INVITE request for the IMS terminal (50) being investigated, sends the INVITE request to the originating fixed IMS network (20), receives a response message via the originating fixed IMS network (20), and determines the usage status of the telephone number of the IMS terminal (50) being investigated based on the elapsed time until the response message (response) is received.

Description

[Technical Field]

[0001] The present invention relates to a telephone number investigation device, investigation method, and investigation program. [Background technology]

[0002] A known prior art technique for determining the usage status of telephone number information is a telephone number information determination device that uses a computer server connected to multiple terminals via an Internet network, and that includes: a database that stores usage history information for multiple telephone numbers; search information receiving means that receives authentication information from the terminal and receives telephone numbers as search information from the terminal on the condition that the authentication means permits login; and system control means that searches the database using the telephone numbers received by the search information receiving means, analyzes changes in the telephone number field to determine whether there are multiple histories of transitions from a subscription state to an unused state in the telephone number history information, and / or analyzes valid changes in the telephone number field to determine whether there are multiple histories of transitions from an unused state to a subscription state in the telephone number history information, and generates history determination information that determines the telephone number in the search information to be a specified subscriber number by referring to unaccumulated history in the telephone number history information, the most recent investigation record in the telephone number history information is unused history, the investigation record one before the most recent investigation record is unused number history, and multiple call termination histories present in the telephone number history information, and displays this history determination information on the terminal via the Internet network (see Patent Document 1).

[0003] Incidentally, with the transition from PSTN (Public Switched Telephone Networks) to NGN (Next Generation Networks), the interconnection interface between operators is also changing from the common channel signaling system SS7 (Signaling System No. 7) to the IP (Internet Protocol) system SIP (Session Initiation Protocol).As a result, specific SIP messages from calling terminals (for example, survey devices that check the usage status of telephone numbers) will reach the IMS (IP Multimedia Subsystem) network, the NGN network, and the IP telephone network (VoIP: Voice over Internet Protocol).

[0004] IMS is a standard for converting services that have previously been provided via fixed networks and mobile communications into IP, thereby enabling integrated multimedia services, and systems built in accordance with this standard include mobile communications systems and NGNs.

[0005] For this reason, it is necessary to ensure a smooth transition to the new system infrastructure by introducing a SIP protocol-based telephone number investigation tool that can be connected to the originating IMS network via UNI (User Network Interface), which uses an IMS interconnection interface or the like for interconnection between operators and determines the usage status of telephone numbers in the terminating IMS network. Therefore, the present applicant has proposed a technology that makes it possible to determine the usage status of telephone numbers in the IMS network by using an IMS interconnection interface or the like for interconnection between operators (see Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-060796 [Patent Document 2] Patent No. 7498920 Summary of the Invention [Problem to be solved by the invention]

[0007] According to the above-mentioned prior art, it is possible to determine the usage status of a telephone number in an IMS network by using an IMS interconnection interface or the like for interconnection between operators, and to determine whether a telephone number is valid (that it actually exists) in the IMS network. However, in the prior art, even if it is determined that the telephone number is valid based on the code of the response from the terminating party, it is not immediately possible to determine whether the telephone number is linked to a mobile phone, a data communication terminal, a busy number, or a temporary disconnection (temporarily disabled due to non-payment of charges, etc.), and it is therefore necessary to analyze the voice guidance transmitted as RTP (Real Time Transport Protocol) from the terminating fixed IMS network to the originating fixed IMS network.

[0008] However, when performing voice guidance analysis on all telephone numbers determined to be valid based on the response code described above, there is a problem in that using voice guidance to determine the usage status of all telephone numbers determined to be valid based on the response code is extremely inefficient.

[0009] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a telephone number research device, a research method, and a research program that enable efficient determination of the usage status of the telephone number being researched. [Means for solving the problem]

[0010] In order to solve the above problems, according to the present invention, there is provided a telephone number investigation device for investigating telephone numbers connected via an originating fixed IMS network to a plurality of IMS terminals connected to a terminating mobile IMS network, the device comprising: a message exchange control unit that adds SDP parameters to an INVITE request for the IMS terminal to be investigated, transmits the INVITE request to the originating fixed IMS network, and receives a response message via the originating fixed IMS network; and a telephone number investigation determination unit that determines the usage status of the telephone number of the IMS terminal to be investigated in accordance with the response message, the SDP parameters describing a network protocol of IPv4, a media type of audio only, a media transport protocol of RTP / AVP only, and voice codecs including G.711μ-law and G.722, and by simultaneously offering G.711μ-law and G.722 as the voice codecs, the device is configured to receive a response from the terminating side with a code 404Not When only G.711 μ-law is offered as the voice codec and the response from the destination side in the case where the IMS terminal to be investigated actually exists is code 183 Session Progress or 180 Ringing, the telephone number investigation determination unit determines that the telephone number of the IMS terminal to be investigated actually exists, and the message exchange control unit stops the ringing of the call bell of the IMS terminal to be investigated by transmitting a CANCEL request to the originating fixed IMS network. Suppress , If the time elapsed until the response code 183 Session Progress or 180 Ringing is received exceeds a predetermined reference time, the IMS terminal associated with the telephone number being investigated After receiving a code 183 Session Progress response or a code 180 Ringing response, the RTP received does not require analysis by voice guidance. If it is determined that the telephone number is a mobile phone and the elapsed time does not exceed a predetermined reference time, the IMS terminal linked to the telephone number being investigated Analysis by voice guidance of the RTP is required Determine whether the terminal is dedicated to data communication, busy, or disconnected for personal reasons A telephone number list is created excluding telephone numbers of terminals determined to be mobile phones from the survey target, based on the telephone number of the survey target telephone number that is determined to be a data communication-only terminal, a busy terminal, or a terminal that has been disconnected due to personal reasons. A telephone number search device is provided.

[0011] The telephone number research method of the present invention further comprises a voice conversion unit in addition to the above configuration. Um, before The message exchange control unit and the telephone number investigation determination unit may be executed based on the telephone number list to determine the usage status of the telephone number of the IMS terminal to be investigated, the voice conversion unit may extract a voice file from the voice guidance after receiving the response with the code 183 Session Progress or 180 Ringing, and may create text data based on the voice file, and based on the text data, it may be determined whether the telephone number to be investigated corresponds to a data communication-only terminal, a busy terminal, or a disconnected terminal due to personal reasons.

[0012] Furthermore, in order to solve the above-mentioned problems, according to the present invention, there is provided a telephone number investigation method for investigating the usage status of telephone numbers of IMS terminals to be investigated, using an apparatus connected to a plurality of IMS terminals connected to a terminating mobile IMS network via an originating fixed IMS network, the method including the steps of: by the apparatus adding SDP parameters to an INVITE request for the IMS terminal to be investigated, and transmitting the INVITE request to the originating fixed IMS network; receiving a response message via the originating fixed IMS network; and determining the usage status of the telephone number of the IMS terminal to be investigated according to the response message, wherein the SDP parameters describe a network protocol of IPv4, a media type of audio only, a media transport protocol of RTP / AVP only, and voice codecs including G.711μ-law and G.722, and by simultaneously offering G.711μ-law and G.722 as the voice codecs, the method is such that when the IMS terminal to be investigated is an unused number, a response from the terminating side returns code 404 Not Found, and when only G.711 μ-law is offered as the voice codec and the IMS terminal being investigated actually exists, if the response from the terminating side is code 183 Session Progress or 180 Ringing, it is determined that the telephone number of the IMS terminal being investigated actually exists, and a CANCEL request is sent to the originating fixed IMS network, thereby preventing the ringing of the call bell of the IMS terminal being investigated. Suppress If the time elapsed until the response code 183 Session Progress or 180 Ringing is received exceeds a predetermined reference time, the IMS terminal associated with the telephone number being investigated A voice guidance message received after receiving a code 183 Session Progress response or a code 180 Ringing response does not require analysis. If it is determined that the telephone number is a mobile phone and the elapsed time does not exceed a predetermined reference time, the IMS terminal linked to the telephone number being investigated Analysis by the voice guidance is required Determine whether the terminal is dedicated to data communication, busy, or disconnected for personal reasons and a step of creating a telephone number list excluding telephone numbers of terminals determined to be mobile phones from the survey target, based on the telephone numbers of the survey target telephone numbers determined to be data communication-only terminals, busy terminals, or disconnected for personal reasons by the step of determining the usage status of the telephone numbers of the IMS terminals. A method for investigating telephone numbers is provided.

[0013] Telephone number research method of the present invention is before The method may further include a step of executing the message exchange control unit and the telephone number investigation determination unit based on the telephone number list to determine the usage status of the telephone number of the IMS terminal to be investigated, extracting an audio file from the audio guidance after receiving the response with code 183 Session Progress or 180 Ringing by the voice conversion unit, and creating text data based on the audio file, and a step of determining based on the text data that the telephone number to be investigated corresponds to any one of a data communication-only terminal, a busy terminal, or a disconnected due to personal reasons.

[0014] Furthermore, a telephone number investigation program of the present invention causes a computer connected to a plurality of IMS terminals connected to a terminating mobile IMS network via an originating fixed IMS network to execute at least the following processes: adding SDP parameters to an INVITE request for the IMS terminal to be investigated, and transmitting the INVITE request to the originating fixed IMS network; receiving a response message via the originating fixed IMS network; and determining a usage status of the telephone number of the IMS terminal to be investigated according to the response message; wherein the SDP parameters describe a network protocol of IPv4, a media type of audio only, a media transport protocol of RTP / AVP only, and voice codecs including G.711μ-law and G.722, and by simultaneously offering G.711μ-law and G.722 as the voice codecs, a response from the terminating side when the IMS terminal to be investigated is an unused number is code 404 Not Found, and when only G.711 μ-law is offered as the voice codec and the IMS terminal being investigated actually exists, if the response from the terminating side is code 183 Session Progress or 180 Ringing, it is determined that the telephone number of the IMS terminal being investigated actually exists, and a CANCEL request is sent to the originating fixed IMS network, thereby preventing the ringing of the call bell of the IMS terminal being investigated. restraintIf the time elapsed until the response code 183 Session Progress or 180 Ringing is received exceeds a predetermined reference time, the IMS terminal linked to the telephone number being investigated is A voice guidance message received after receiving a code 183 Session Progress response or a code 180 Ringing response does not require analysis. If the time elapsed does not exceed a predetermined reference time, the telephone number of the investigation target is determined to be a mobile phone. IMS The device Analysis by the voice guidance is required Determined to be a data communication-only terminal, busy, or disconnected for personal reasons and performing a process of determining the usage status of the telephone number of the IMS terminal, and performing a process of creating a telephone number list excluding the telephone numbers of the terminals determined to be the mobile phones from the survey target, based on the telephone number of the survey target that is determined to be a data communication-only terminal, a busy terminal, or a terminal that has been disconnected due to personal reasons. do.

[0015] The telephone number search program of the present invention is before The method may further include a process of executing the message exchange control unit and the telephone number investigation determination unit based on the telephone number list to determine the usage status of the telephone number of the IMS terminal to be investigated, extracting an audio file from the audio guidance after receiving the response with code 183 Session Progress or 180 Ringing by the voice conversion unit and creating text data based on the audio file, and a process of determining based on the text data whether the telephone number to be investigated corresponds to a data communication-only terminal, a busy terminal, or a disconnection due to personal reasons. [Effects of the Invention]

[0016] According to one aspect of the present invention, it is possible to create a telephone number list that excludes (screens) telephone numbers that can be determined to be real and mobile phone numbers without analyzing all voice guidance. In other words, it is possible to create a telephone number list that extracts telephone numbers that need to be determined by analyzing voice guidance such as data communication-only terminals, temporary disconnection, busy, etc. from the telephone number list to be investigated.

[0017] In another aspect, the present invention makes it possible to significantly reduce the time required to check the usage status of all telephone numbers to be investigated. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic diagram showing a network connection configuration of a telephone number research device according to an embodiment of the present invention; [Figure 2] FIG. 1 is a conceptual diagram showing pattern 1 of the basic sequence of operations between a calling device, a calling fixed IMS network, and a called mobile IMS network when a mobile phone is actually present as the called device and is not in use. [Figure 3] FIG. 10 is a conceptual diagram showing pattern 2 of the basic sequence of operations between a calling device, a calling fixed IMS network, and a called mobile IMS network when a mobile phone is actually present as the called device and is not in use. [Figure 4] FIG. 10 is a diagram illustrating a first pattern of a basic sequence of operations between a calling device, a calling fixed IMS network, and a called mobile IMS network when a data communication-only terminal actually exists as a called device. [Figure 5] FIG. 10 is a conceptual diagram showing pattern 2 of the basic sequence of operations between a calling device, a calling fixed IMS network, and a called mobile IMS network when a data-only terminal is actually present as the called device. [Figure 6] FIG. 1 is a conceptual diagram showing the basic sequence of operations between a calling device, a calling fixed IMS network, and a called mobile IMS network when a mobile phone is actually present as the called device and is in use. [Figure 7] Conceptual diagram showing the basic sequence when the IMS terminal being investigated has an unused number (simultaneous offer of G.711 μ-law and G.722). [Figure 8] FIG. 1 is a conceptual diagram showing a basic sequence of operations between a calling device, a calling fixed IMS network, and a called mobile IMS network when a called device is disconnected for personal reasons. [Figure 9] FIG. 2 is a block diagram showing the configuration of the telephone number investigation device of FIG. 1. [Figure 10] 9 is a flowchart showing the processing of a survey program relating to a telephone number survey method executed by the telephone number survey device shown in FIG. 8; [Figure 11]FIG. 10 is a conceptual diagram showing an operation sequence when the telephone number investigation method shown in FIG. 9 is executed. [Figure 12] A schematic diagram showing the method for investigating the usage status of telephone numbers on IMS terminals. [Figure 13] 1 is a system configuration diagram of a telephone number information providing system according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a telephone number research device, a research method, and a research program configured based on the present invention will be described with reference to the accompanying drawings.

[0020] (Network connection type) FIG. 1 is a schematic diagram showing a network connection configuration including a telephone number research device 10 according to this embodiment.

[0021] A telephone number investigation device 10 according to the embodiment is connected to a plurality of terminals to be investigated (specifically, IMS terminals 50a, 50b, 50c) connected to a destination mobile IMS network 30 (for example, an IP telephone network (VoIP: Voice Over Internet Protocol)) via a source fixed IMS network 20 (specifically, for example, an NGN network). The IMS terminals 50a, 50b, 50c include mobile phones and terminals dedicated to data communication. In the following description of the embodiment, when it is not necessary to distinguish between the IMS terminals 50a, 50b, 50c for each network (in other words, for each contracted carrier or contracted business), they will simply be referred to as "IMS terminals 50."

[0022] The originating fixed IMS network 20 includes a SIP server 20a, which manages and controls the operation of the originating fixed IMS network 20. The terminating mobile IMS network 30 includes SIP servers 30a, 30b, and 30c, which manage and control the operation of the terminating mobile IMS network 30.

[0023] The terminating mobile IMS network 30 is constructed for each telecommunications carrier (in the example shown in FIG. 1, carrier A, carrier B, and carrier C), and IMS terminals 50a, 50b, and 50c are connected to each network (in other words, for each contracted carrier or contracted operator) via SIP servers 30a, 30b, and 30c managed and operated by each carrier.

[0024] The terminating mobile IMS network 30 supports at least the IP (Internet Protocol) v4 network protocol (in other words, the Internet Protocol, IP version) for SDP (Session Description Protocol) parameters, supports audio as the media type, supports RTP / AVP as the media transport protocol, and requires G.711 μ-law as the audio codec.

[0025] In the telephone number investigation device, investigation method, and investigation program of this embodiment, the investigation targets mobile phones (mobile terminals) and data communication-only terminals having telephone numbers of 0A0 type (specifically, for example, 090, 080, and 070), and assumes an IMS terminal 50 connected to a terminating mobile IMS network 30, which is the network on the receiving side.

[0026] 1, a telephone number investigation device 10, which is a calling device, has a list of telephone numbers to be investigated, and dials the telephone numbers of IMS terminals 50a, 50b, and 50c connected to a called mobile IMS network 30 as the telephone numbers of the called terminals, thereby routing is performed in the order of a SIP server 20a in a called fixed IMS network 20, a calling IBCF (Interconnection Border Control Function) 21, a called IBCF 31, the SIP servers 30a, 30b, and 30c, and the called IMS terminals 50a, 50b, and 50c. In investigating a telephone number in this embodiment, as will be described below, the telephone number investigation device 10, which is a calling device, sets the caller number to be withheld (specifically, adds the number "184" before the telephone number of the called party), and then dials the telephone number to be investigated.

[0027] At this time, a UNI connection is ensured between the telephone number research device 10 and the originating fixed IMS network 20, and the inter-operator interconnection between the originating fixed IMS network 20 and the terminating mobile IMS network 30 is ensured via an IMS interconnection interface (specifically, the originating IBCF 21 and the terminating IBCF 31), etc., and a specific SIP message (details will be described later) sent from the telephone number research device 10 in accordance with the SIP signaling method reaches the terminating mobile IMS network 30.

[0028] In the example shown in Figure 1, the NNI (Network-Network Interface), which is a common interface for interconnection between IMS operators via IP-IP connections, is specified in the TTC standard JJ-90.30 (TTC: Telecommunication Technology Committee; a general incorporated association).

[0029] According to SIP, in order to carry out real-time communication, negotiations must be carried out between terminals regarding the encoding method of packets containing media information, addresses of packet destinations, etc. This negotiation requires a description language called SDP (Session Description Protocol), which is defined in the TTC standard RFC4566.

[0030] To establish a session using SIP, the calling party first sends a request that describes media information in a SIP message, and the called party then replies with a response that selects the media that it can support, thereby sharing the media information to be used for communication between the calling party and the called party.

[0031] Sending a SIP message with media information to start a session is called an offer, and returning available media information in response is called an answer. This offer / answer model is defined in the TTC standard RFC3264. Furthermore, the SDP media negotiation procedure in IMS is specified in the TTC standard JJ-90.26.

[0032] The telephone number research device 10 in the embodiment shown in FIG. 1, when sending an SDP offer (hereinafter referred to as "INVITE request") of the INVITE method to the IMS terminal 50 to be researched via the originating fixed IMS network 20 (including SIP server 20a) and the terminating mobile IMS network 30 (including SIP servers 30a, 30b, 30c), adds (in other words, describes) a predetermined SDP parameter (hereinafter referred to as "SDP parameter for determination") to the SDP offer and transmits it.

[0033] The determination SDP parameters added to the SDP parameters when the INVITE request is sent are the network protocol (in other words, Internet Protocol, IP version), media type, media transport protocol, and audio codec.

[0034] In response to the INVITE request, the IMS terminal 50 on the receiving side compares the SDP parameters included in the INVITE request with the SDP parameters that it can use, and depending on the result of the comparison (i.e., whether the SDP parameters match or mismatch), returns a response with a predetermined code in the SIP session as a response message.

[0035] Then, the telephone number research device 10 determines the usage status of the IMS terminal 50 on the receiving side based on the information about the response of the received predetermined code.

[0036] (basic sequence) 2 to 7 are diagrams illustrating a basic sequence of operations between a calling device, the calling fixed IMS network 20, and the called mobile IMS network 30 using the INVITE method in IMS interconnection, when the IMS terminal 50 serving as the called device is a mobile phone or a data communication-only terminal. The basic sequence of operations between the calling device (specifically, the telephone number research device 10) and the IMS terminal 50 according to this embodiment, as shown in FIGS. 2 to 7, is merely an example and may differ depending on the contracted carrier or the contracted business. In such cases, the operations should conform to the specifications of, for example, TTC Standard JJ-90.30, TTC Standard JJ-90.26, TTC Standard JF-IETF-RFC3398, TTC Standard TR-1088, TTC Standard JT-Q850, and TTC Specification TS-1025.

[0037] Communication is performed between the calling device and the called device (specifically, a mobile phone) connected to the called mobile IMS 30 via the calling fixed IMS network 20, the calling IBCF 21, the called IBCF 31, and the called mobile IMS network 30.

[0038] (If the mobile phone is real / Pattern 1) FIG. 2 is a diagram illustrating a basic sequence pattern 1 of an operation performed by the INVITE method in IMS interconnection between a calling device, an originating fixed IMS network 20, and a terminating mobile IMS network 30, when a mobile phone is actually present as the called device and is not busy, and the calling device disconnects communication.

[0039] 2 is a diagram illustrating a basic sequence when the caller has set the phone number to be anonymous and there is no setting to reject incoming calls. Here, there are two ways to set the setting to reject incoming calls: using a service provided by a carrier (telecommunications operator) (referred to as a "anonymous call rejection service"), or using a function provided in the IMS terminal 50 itself (referred to as a "anonymous call rejection function"). In other words, FIG. 2 is a diagram illustrating a basic sequence when the anonymous call rejection service and anonymous call rejection function are not set.

[0040] The calling device sends an INVITE request to the called device via the calling fixed IMS network 20 and then via the called mobile IMS network 30, such as a mobile phone network of the carrier of the called device's contract (F1). In response to this, the calling fixed IMS network 20 sends an INVITE request to the called mobile IMS network 30 (F2).

[0041] In response to this, the terminating mobile IMS network 30 returns a code 100 Trying response to the originating fixed IMS network 20 indicating that the request has been accepted in the SIP session (F3), and in response to this, the originating fixed IMS network 20 returns a code 100 Trying response to the calling device (F4).

[0042] Next, the terminating mobile IMS network 30 returns a code 183 Session Progress response indicating the progress of the call in the SIP session to the originating fixed IMS network 20 (F5), and in response, the originating fixed IMS network 20 returns a code 183 Session Progress response to the calling device (F6).

[0043] At this time, the call bell of the receiving device (specifically, the mobile phone) rings, and an RBT (Ringing Back Tone) is sent as RTP (Real-time Transport Protocol) from the receiving mobile IMS network 30 to the calling device via the originating fixed IMS network 20 (F7).

[0044] Next, the terminating mobile IMS network 30 returns a code 200 OK response to the originating fixed IMS network 20, indicating that the request (specifically, the INVITE request and confirmation of SDP information) has been successfully processed in the SIP session (F8). In response to this, the originating fixed IMS network 20 returns a code 200 OK response to the calling device (F9).

[0045] In response to this, an ACK (Acknowledgment) response indicating an acknowledgment in the SIP session is returned from the calling device to the calling fixed IMS network 20 (F10), and in response to this, the calling fixed IMS network 20 returns an ACK response to the called mobile IMS network 30 (F11). Then, a session is established between the calling device and the called device, and communication (call) is started.

[0046] Thereafter, (in the example shown in FIG. 2, when the calling device disconnects the communication) a BYE request indicating the end of the SIP session is sent from the calling device to the calling fixed IMS network 20 (F12), and in response to this, a BYE request is sent from the calling fixed IMS network 20 to the called mobile IMS network 30 (F13).

[0047] In response to this, the terminating mobile IMS network 30 returns a code 200 OK response (BYE) indicating that the request (specifically, the BYE request) has been successfully processed in the SIP session to the originating fixed IMS network 20 (F14), and in response to this, the originating fixed IMS network 20 returns a code 200 OK response (BYE) to the calling device (F15). This ends the session between the calling device and the called device, i.e., the communication (call) between the calling device and the called device is disconnected.

[0048] In the basic sequence shown in FIG. 2, an INVITE request is sent to a called device via the originating fixed IMS network 20, and the elapsed time T1 required for a code 183 Session Progress response (F6) to be returned from the originating fixed IMS network 20 to the calling device is measured multiple times. The average elapsed time T1 was 1.95 seconds.

[0049] (If the mobile phone is real / Pattern 2) FIG. 3 is a diagram illustrating another pattern 2 of the basic sequence of operations in an INVITE method in IMS interconnection between a calling device, an originating fixed IMS network 20, and a terminating mobile IMS network 30, when a mobile phone is actually present as the called device and is not busy, and the calling device disconnects communication.

[0050] Fig. 3 is a diagram illustrating a basic sequence when the anonymous call rejection service and anonymous call rejection function are not set, similar to Fig. 2. Note that the content of pattern 1 of the basic sequence shown in Fig. 2 and pattern 2 of the basic sequence shown in Fig. 3 differ due to, for example, different contracted carriers of the IMS terminal 50.

[0051] The operations F1 to F7 in pattern 2 of the basic sequence shown in FIG. 3 are the same as the operations F1 to F7 in pattern 1 of the basic sequence explained with reference to FIG. 2, and detailed explanations thereof will be omitted.

[0052] In pattern 2 of the basic sequence shown in FIG. 3 , an RBT (Ringing Back Tone) is transmitted as an RTP (Real-time Transport Protocol) from the terminating mobile IMS network 30 to the calling device via the originating fixed IMS network 20 (F7), and a code 180 Ringing response indicating that a ring tone has sounded in the SIP session is returned from the terminating mobile IMS network 30 to the originating fixed IMS network 20 (F8). In response to this, a code 180 Ringing response is returned from the originating fixed IMS network 20 to the calling device (F9).

[0053] In basic sequence pattern 2 shown in Fig. 3, the operations F10 to F17 after the code 180 Ringing response is returned (F8, F9) are the same as the operations F8 to F15 in basic sequence pattern 1 described with reference to Fig. 2, and detailed description thereof will be omitted. Then, the session between the calling device and the called device is terminated, that is, the communication (call) between the calling device and the called device is disconnected.

[0054] In the basic sequence shown in FIG. 3, an INVITE request is sent to the called device via the originating fixed IMS network 20 and then via the terminating mobile IMS network 30, such as a mobile phone network of the carrier of the contract of the called device. The elapsed time T2 required for the originating fixed IMS network 20 to return a code 183 Session Progress response (F6) to the calling device was measured multiple times, and the average elapsed time T2 was 1.99 seconds.

[0055] Incidentally, in a basic sequence of operations by the INVITE method in IMS interconnection between a calling device, an originating fixed IMS network 20, and a terminating mobile IMS network 30 when a mobile phone is actually present but busy as the called device (i.e., a basic sequence when neither the anonymous call rejection service nor the anonymous call rejection function is set; see Figures 2 and 3), the normal sequence is an operation in which a code 183 Session Progress response (F5, F6) is returned in response to an INVITE request (F1, F2) from the calling device. However, depending on the contracted carrier of the IMS terminal 50, an irregular response may occur in which a code 180 Ringing response is returned instead of a code 183 Session Progress response. In this case, an INVITE request is sent to the called device via the originating fixed IMS network 20 and then via the terminating mobile IMS network 30, such as a mobile phone network of the carrier of the contract of the called device, and the elapsed time T2' until a code 180 Ringing response is returned from the originating fixed IMS network 20 to the calling device is equal to T2.

[0056] (For data-only devices) 4 and 5 are diagrams illustrating a basic sequence of operations between a calling device, the calling fixed IMS network 20, and the called mobile IMS network 30 when the IMS terminal 50 as the called device is a data communication-only terminal by the INVITE method in IMS interconnection. Note that the basic sequence of operations related to the calling device according to this embodiment (specifically, the telephone number research device 10) and the IMS terminal 50, which is a data communication-only terminal, is not limited to the content shown in FIGS. 4 and 5, but may also comply with the content specified in, for example, TTC Standard JJ-90.30, TTC Standard JJ-90.26, TTC Standard JF-IETF-RFC3398, TTC Standard TR-1088, TTC Standard JT-Q850, and TTC Specification TS-1025.

[0057] Communication is carried out between the calling device and the called device (specifically, a data communication-only terminal) connected to the called mobile IMS network 30 via the calling fixed IMS network 20, the calling IBCF 21, the called IBCF 31, and the called mobile IMS network 30.

[0058] (Basic sequence / pattern 1 for data communication-only terminals) FIG. 4 is a diagram illustrating a basic sequence pattern 1 of an operation by the INVITE method in IMS interconnection between a calling device, a calling fixed IMS network 20, and a called mobile IMS network 30, when a data-only terminal actually exists as a called device.

[0059] The calling device sends an INVITE request to the called device via the calling fixed IMS network 20 and then via the called mobile IMS network 30, such as a mobile phone network of the carrier of the called device's contract (F1).In response to this, the calling fixed IMS network 20 sends an INVITE request to the called mobile IMS network 30 (F2).

[0060] In response to this, the terminating mobile IMS network 30 returns a code 100 Trying response to the originating fixed IMS network 20 indicating that the request has been accepted in the SIP session (F3), and in response to this, the originating fixed IMS network 20 returns a code 100 Trying response to the calling device (F4).

[0061] Next, the terminating mobile IMS network 30 returns a code 183 Session Progress response indicating the progress of the call in the SIP session to the originating fixed IMS network 20 (F5), and in response, the originating fixed IMS network 20 returns a code 183 Session Progress response to the calling device (F6).

[0062] Furthermore, the terminating mobile IMS network 30 sends a guidance message to the calling device via the originating fixed IMS network 20, informing the calling device that the called device is dedicated to data communication (F7).

[0063] Next, the terminating mobile IMS network 30 returns a code 480 Temporarily Unavailable response to the originating fixed IMS network 20, indicating that the media resource requested by the originating party in the SIP session (i.e., the terminating party's equipment) is temporarily unavailable (F8). In response to this, the originating fixed IMS network 20 returns a code 480 Temporarily Unavailable response to the originating party's equipment (F9).

[0064] In response to this, an ACK (Acknowledgment) response indicating an acknowledgment in the SIP session is returned from the originating device to the originating fixed IMS network 20 (F10), and in response to this, an ACK response is returned from the originating fixed IMS network 20 to the terminating mobile IMS network 30 (F11). This ends the session related to the INVITE request from the originating device.

[0065] In the basic sequence shown in FIG. 4, an INVITE request is sent to the called device via the originating fixed IMS network 20 and then via the terminating mobile IMS network 30, such as a mobile phone network of the carrier of the contract of the called device. When the elapsed time T3 required for the originating fixed IMS network 20 to return a code 183 Session Progress response (F6) to the calling device was measured multiple times, the average elapsed time T3 was 0.65 seconds.

[0066] (Basic sequence / pattern 2 for data communication-only terminals) FIG. 5 is a diagram illustrating a second pattern of a basic sequence of operations performed by the INVITE method in IMS interconnection between a calling device, a calling fixed IMS network 20, and a called mobile IMS network 30, when a data-only terminal is actually present as the called device.

[0067] The basic sequence patterns 1 and 2 shown in FIGS. 4 and 5 have different contents due to, for example, the contracted carriers or contracted businesses of the IMS terminal 50 being different.

[0068] The operations F1 to F6 in pattern 2 of the basic sequence shown in FIG. 5 are the same as the operations F1 to F6 in pattern 1 of the basic sequence shown in FIG. 4, and detailed description thereof will be omitted.

[0069] In pattern 2 of the basic sequence shown in Figure 5, following the operation of F6, guidance is sent from the terminating mobile IMS network 30 to the calling device via the originating fixed IMS network 20, indicating that the device cannot be connected to the terminating device (F7).

[0070] Next, the terminating mobile IMS network 30 returns a code 403 Forbidden response to the originating fixed IMS network 20, indicating that access to the media resource (i.e., the terminating device) requested by the originating device in the SIP session is prohibited (F8). In response to this, the originating fixed IMS network 20 returns a code 403 Forbidden response to the originating device (F9).

[0071] In response to this, an ACK (Acknowledgment) response indicating an acknowledgment in the SIP session is returned from the originating device to the originating fixed IMS network 20 (F10), and in response to this, an ACK response is returned from the originating fixed IMS network 20 to the terminating mobile IMS network 30 (F11). This ends the session related to the INVITE request from the originating device.

[0072] In the basic sequence shown in FIG. 5, an INVITE request is sent to the terminating device via the originating fixed IMS network 20 and then via the terminating mobile IMS network 30, such as a mobile phone network of the carrier of the subscribed carrier of the terminating device. When the elapsed time T4 required for the originating fixed IMS network 20 to return a code 183 Session Progress response (F6) to the originating device was measured multiple times, the average elapsed time T4 was 0.48 seconds.

[0073] (If your cell phone is busy) 6 is a diagram illustrating a basic sequence of operations in IMS interconnection using the INVITE method when a mobile phone is actually present and busy as the called device, between a calling device, an originating fixed IMS network 20, and a called mobile IMS network 30. This basic sequence is specified in the TTC standard TR-1088.

[0074] The calling device sends an INVITE request to the called device via the calling fixed IMS network 20 and then via the called mobile IMS network 30, such as a mobile phone network of the carrier of the called device's contract (F1). In response to this, the calling fixed IMS network 20 sends an INVITE request to the called mobile IMS network 30 (F2).

[0075] In response to this, the terminating mobile IMS network 30 returns a code 100 Trying response to the originating fixed IMS network 20 indicating that the request has been accepted in the SIP session (F3), and in response to this, the originating fixed IMS network 20 returns a code 100 Trying response to the calling device (F4).

[0076] Next, the terminating mobile IMS network 30 returns a code 183 Session Progress response indicating the progress of the call in the SIP session to the originating fixed IMS network 20 (F5), and in response, the originating fixed IMS network 20 returns a code 183 Session Progress response to the calling device (F6).

[0077] Furthermore, a busy tone indicating that the receiving device is busy is sent as RTP (Real Time Transport Protocol) from the receiving mobile IMS network 30 to the calling device via the originating fixed IMS network 20 (F7).

[0078] Next, the terminating mobile IMS network 30 returns a code 487 Request Terminated response to the originating fixed IMS network 20, indicating the termination of the request in the SIP session (in other words, the end of the session) (F8). In response to this, the originating fixed IMS network 20 returns a code 487 Request Terminated response to the calling device (F9).

[0079] In response to this, an ACK (Acknowledgment) response indicating an acknowledgment in the SIP session is returned from the originating device to the originating fixed IMS network 20 (F10), and in response to this, an ACK response is returned from the originating fixed IMS network 20 to the terminating mobile IMS network 30 (F11). This ends the session related to the INVITE request from the originating device.

[0080] In the basic sequence shown in FIG. 6, an INVITE request is sent to the called device via the originating fixed IMS network 20 and then via the terminating mobile IMS network 30, such as a mobile phone network of the carrier of the contract of the called device. When the elapsed time T5 required for the originating fixed IMS network 20 to return a code 183 Session Progress response (F6) to the calling device was measured multiple times, the average elapsed time T5 was 0.83 seconds.

[0081] (If the phone number is missing) FIG. 7 is a diagram illustrating the basic sequence of operations in IMS interconnection between a calling device, a calling fixed IMS network 20, and a called mobile IMS network 30 when G.711μ-law and G.722 are offered simultaneously as voice codecs, and the called device (in other words, the telephone number) is an unused number.

[0082] The calling device sends an INVITE request to the called device via the calling fixed IMS network 20 and then via the called mobile IMS network 30, such as a mobile phone network of the carrier of the called device's contract (F1). In response to this, the calling fixed IMS network 20 sends an INVITE request to the called mobile IMS network 30 (F2).

[0083] In response to this, the terminating mobile IMS network 30 returns a code 100 Trying response to the originating fixed IMS network 20 indicating that the request has been accepted in the SIP session (F3), and in response to this, the originating fixed IMS network 20 returns a code 100 Trying response to the calling device (F4).

[0084] Next, the terminating mobile IMS network 30 returns a code 404 Not Found response to the originating fixed IMS network 20, indicating that the media resource requested by the originating side in the SIP session cannot be found (F5), and in response, the originating fixed IMS network 20 returns a 404 Not Found response to the originating side's device (F6).

[0085] In response to this, an ACK (Acknowledgment) response indicating an acknowledgment in the SIP session is returned from the originating device to the originating fixed IMS network 20 (F7), and in response to this, an ACK response is returned from the originating fixed IMS network 20 to the terminating mobile IMS network 30 (F8), thereby completing the session related to the INVITE request from the originating device.

[0086] 8 is a diagram illustrating the basic sequence of operations performed by the INVITE method in IMS interconnection between an originating device, an originating fixed IMS network 20, and a terminating mobile IMS network 30 when the terminating IMS terminal 50 is in a voluntary detachment state (temporarily disabled due to unpaid charges, etc.). This basic sequence is defined in the TTC standard TR-1088. The originating device sends an INVITE request to the terminating device via the originating fixed IMS network 20 and the terminating mobile IMS network 30, such as the mobile phone network of the terminating device's contract carrier (F1). In response to this, the originating fixed IMS network 20 sends an INVITE request to the terminating mobile IMS network 30 (F2). In response to this, the terminating mobile IMS network 30 returns a code 100 Trying response to the originating fixed IMS network 20, indicating that the request has been accepted in the SIP session (F3), and in response to this, the originating fixed IMS network 20 returns a code 100 Trying response to the calling device (F4). In this case, depending on the contracted carrier, the terminating mobile IMS network 30 returns a code 183 Session Progress response to the originating fixed IMS network 20, indicating the progress of the call in the SIP session (F5), and in response to this, the originating fixed IMS network 20 returns a code 183 Session Progress response to the calling device (F6), followed by a guidance message indicating that the call will be disconnected due to personal reasons (unable to connect).

[0087] In the basic sequence for such a case, an INVITE request is sent to the terminating device via the originating fixed IMS network 20 and then via the terminating mobile IMS network 30, such as the mobile phone network of the carrier of the terminating device's contract, and the elapsed time T6 required for the originating fixed IMS network 20 to return a code 183 Session Progress response to the originating device is measured.The measured time was an average of less than 1.0 second (e.g., 0.95 seconds), similar to when the IMS terminal 50 is a data communication-only terminal or when the IMS terminal 50 is busy.

[0088] (telephone number investigation device) FIG. 9 is a block diagram showing the configuration of a telephone number research device 10 according to an embodiment.

[0089] The telephone number investigation device 10 of this embodiment is configured by a computer and includes a network interface unit 11, a message exchange control unit 12, a telephone number investigation determination unit 13, a telephone number history generation unit 14, a voice conversion unit 15, and a telephone number history database (DB) 16.

[0090] As shown in FIG. 1, the telephone number investigation device 10 according to the embodiment is connected to a plurality of IMS terminals 50 connected to a terminating mobile IMS network 30 via an originating fixed IMS network 20, and, for example, adds SDP parameters to an INVITE request addressed to the IMS terminal 50 linked to the telephone number to be investigated and sends the INVITE request to the originating fixed IMS network 20 (towards the IMS terminal 50 to be investigated), receives a response message via the originating fixed IMS network 20, and determines the usage status of the telephone number of the IMS terminal 50 to be investigated based on the response message.

[0091] The network interface unit 11 functions as a communication interface for the telephone number research device 10 to perform communication in accordance with the SIP protocol.

[0092] The message exchange control unit 12 sends an INVITE request including SDP parameters for determination to the IMS terminal 50 to be investigated, and also receives a signal (e.g., a response with a predetermined code in a SIP session) from the terminating mobile IMS network 30 (including SIP servers 30a, 30b, and 30c).

[0093] The telephone number investigation determination unit 13 determines whether the IMS terminal 50 to be investigated on the receiving side actually exists or not, depending on the message received via the message exchange control unit 12 (for example, a response with a specified code in a SIP session), and further determines the validity of the telephone number of the IMS terminal 50 to be investigated (in other words, the usage status of the telephone number) by analyzing the text data of the voice guidance converted by the voice conversion unit 15 described later.

[0094] The telephone number history generation unit 14 constructs a telephone number history database 16 for the telephone numbers that have been investigated by assigning a timestamp indicating the date and time of the judgment to each judgment result from the telephone number investigation judgment unit 13 and recording them in chronological order on a recording medium.

[0095] The voice conversion unit 15 is equipped with a voice guidance call control server (neither of which is shown) that records (in other words, packet captures) any voice guidance that is transmitted and stores it as voice data, and when a code 183 Session Progress response is returned following the voice guidance, stores the recorded and stored voice data in memory or a storage device.

[0096] The speech conversion unit 15 also includes a speech recognition unit (not shown) that converts the stored speech data into text (i.e., speech to text) and stores the converted text data in a memory or storage device (neither of which are shown). The text data is then analyzed by the telephone number investigation determination unit 13 to determine whether the IMS terminal 50 being investigated is a data communication-only terminal, is busy, is disconnected due to personal reasons, etc. In this way, the telephone number history database 16 is constructed by assigning a timestamp indicating the date and time of the determination to each determination result by the telephone number investigation determination unit 13 based on the text data and recording them in chronological order on a recording medium.

[0097] Although the data structure of the telephone number history database 16 (in other words, the included data items) is not limited to a specific structure or items, the telephone number history information stored in the telephone number history database 16 may include, for example, a combination of the "telephone number" being investigated for each investigation (in other words, for each transmission of an INVITE request), the "error code" returned from the terminating mobile IMS network 30, the "investigation date" (i.e., a timestamp), "information such as the result of the determination of whether the number exists or is missing," the type of IMS terminal 50 being investigated (specifically, a mobile phone or a data communication-only terminal), "busy," "disconnected due to personal reasons," and "other layer information" regarding the layer returned from the terminating mobile IMS network 30.

[0098] In addition to the data items mentioned above, the telephone number history information stored in telephone number history database 16 may also include, for example, a "new subscriber number" which is the new or contact telephone number discovered during the investigation, the "corporate name / individual name" which owns the telephone number, "attribute information" such as address and age, "map link information," and "credit information" for assessing creditworthiness.

[0099] Then, for example, when the telephone number investigation device 10 investigates the usage status of the telephone number "090-XXXX-XXXX", the investigation information is recorded sequentially in the telephone number history database 16 for each determination made by the telephone number investigation determination unit 13, and is accumulated and stored as history information.

[0100] The telephone number history database 16 may be implemented on a large-capacity recording medium such as a semiconductor memory, a hard disk, or an optical memory such as a DVD (Digital Versatile Disc).

[0101] The telephone number research device 10 is configured to include a microprocessor having built-in memory (not shown) in which a predetermined program (including the telephone number research program according to the embodiment) is recorded, or a microprocessor to which an external memory (not shown) in which a predetermined program is recorded, and an LSI (Large Scale Integration) that performs peripheral control including communication control.

[0102] The microprocessor sequentially reads and executes predetermined programs (including programs for implementing the telephone number research method of this embodiment) recorded in memory (not shown), thereby configuring the network interface unit 11, message exchange control unit 12, telephone number research determination unit 13, telephone number history generation unit 14, and voice conversion unit 15, and realizing the predetermined functions of the telephone number research device 10.

[0103] (How to research phone numbers) The inventors of the present application have conducted a detailed study on the actual operation of the above-mentioned basic sequence for each terminating mobile IMS network 30, in other words, for each contracted carrier or contracted business, in terms of the time elapsed from when an INVITE request is sent to a terminating device via a terminating mobile IMS network 30 such as a mobile phone network of the contracted carrier of the terminating device through an originating fixed IMS network 20 until the originating device receives a code 183 Session Progress response (F6) (or a 180 Ringing response) from the originating fixed IMS network 20.

[0104] As a result of the above investigation, it was found that the elapsed time (T1, T2 (T2')) until the response message (code 183 Session Progress or code 180 Ringing) is received by the telephone number investigation device 10 when it is determined that the telephone number of the IMS terminal being investigated is real and is not a data communication-only terminal, busy, or disconnected for personal reasons is approximately just under 2 seconds (for example, 1.95 seconds, 1.99 seconds).

[0105] Furthermore, it was found that when the telephone number of the IMS terminal being investigated is real and is either a data communication-only terminal, busy, or disconnected due to personal reasons, the elapsed time (T3, T4, T5, T6) until the response message (code 183 Session Progress, or code 180 Ringing) is received by the telephone number investigation device 10 is, on average, approximately no more than 1 second (for example, 0.65 seconds, 0.48 seconds, 0.83 seconds, 0.95 seconds).

[0106] In this embodiment, a telephone number investigation method according to the present embodiment is implemented based on the above-described findings. For example, by simultaneously offering G.711 μ-law and G.722 as the voice codecs, the response from the terminating side when the IMS terminal to be investigated is an unused number is set to code 404 Not Found (this is omitted from the illustrated flowchart). When only G.711 μ-law is offered (INVITE is sent) as the voice codec, if the response from the terminating side when the IMS terminal 50 to be investigated actually exists is code 183 Session Progress or 180 Ringing, the telephone number investigation determination unit 13 determines that the telephone number of the IMS terminal 50 to be investigated actually exists, and the message exchange control unit 12 transmits a CANCEL request to the originating fixed IMS network 20, thereby suppressing or immediately stopping the ringing of the call bell of the IMS terminal 50 to be investigated. Then, it is determined whether the elapsed time T until the response code 183 Session Progress or 180 Ringing is received exceeds a predetermined reference time T0 (for example, T0 = 1.1 seconds), and if the elapsed time T exceeds the predetermined reference time T0, it is determined that the IMS terminal 50 linked to the telephone number being investigated is a mobile phone, and if the elapsed time T does not exceed the predetermined reference time T0, it is determined that the IMS terminal 50 linked to the telephone number being investigated is either a data communication-only terminal, a busy terminal, or a terminal disconnected due to personal reasons.

[0107] As described above, it is possible to separate the telephone numbers registered in the list of telephone numbers to be investigated into those that are actual mobile phone numbers and those that are not (data communication-only terminals, busy numbers, and numbers removed for personal reasons). Then, from the list of telephone numbers to be investigated, telephone numbers that have been found to be actual mobile phone numbers are excluded (in other words, screened), and a list of telephone numbers that require confirmation by voice guidance, which will be explained later (hereinafter referred to as the "limited telephone number list") is created, and stored in an appropriate memory of the telephone number investigation device 10.

[0108] In addition, in this embodiment, the telephone number investigation device 10 is provided with a voice conversion unit 15, and based on the limited telephone number list, the message exchange control unit 12 and the telephone number investigation determination unit 13 are executed to extract a voice file from the voice guidance after receiving the response code 183 Session Progress or 180 Ringing, and create text data based on the voice file, and based on the text data, determine whether the IMS terminal 50 to be investigated is a data communication-only terminal, busy, or disconnected due to personal reasons. At this time, the reference time T0 is set to, for example, 1.1 seconds based on an analysis of the elapsed time T until the telephone number research device 10 receives the response message (code 183 Session Progress or code 180 Ringing). Note that the reference time T0 is determined based on a test research conducted in advance so as to exclude the response time T when the IMS terminal 50 linked to the telephone number to be researched is a data communication-only terminal, is busy, or is disconnected due to personal reasons. As described above, the reference time T0 is not limited to being set to 1.1 seconds, and can be set arbitrarily within the range of, for example, 1.1 seconds to 1.9 seconds.

[0109] As an example of a specific configuration of the telephone number investigation method according to this embodiment, the telephone number investigation method according to this embodiment is a method of investigating the usage status of the telephone number to be investigated using a computer (specifically, a telephone number investigation device 10) connected to multiple IMS terminals 50 connected to the terminating mobile IMS network 30 via the originating fixed IMS network 20, and can be implemented, for example, by a program configured based on the flowchart shown in Figure 10.

[0110] The flowchart shown in FIG. 10 shows an outline of the telephone number research method of this embodiment, and some of the specific configuration of the research method is omitted as appropriate.

[0111] The program includes step S1 of starting a program configured based on the illustrated flowchart (START), adding SDP parameters to an INVITE request for the IMS terminal 50 being investigated in the telephone number investigation device 10, and sending the INVITE request to the originating fixed IMS network 20 (toward the IMS terminal 50 being investigated), step S2 of receiving a response message via the originating fixed IMS network 20, steps S3 to S5 of determining the usage status of the telephone number of the IMS terminal 50 being investigated based on the response message, and step S6 of creating a limited call list.

[0112] The SDP parameters describe that the network protocol is IPv4, the media type is audio only, the media transport protocol is RTP / AVP only, and the voice codec includes G.711 μ-law and G.722, and by simultaneously offering G.711 μ-law and G.722 as the voice codec, if the IMS terminal being investigated is an unused number, the response from the terminating side is code 404 Not Found, and if only G.711 μ-law is offered as the voice codec and the response from the terminating side is code 183 Session Progress or 180 Ringing if the IMS terminal being investigated actually exists, it is determined that the telephone number of the IMS terminal being investigated actually exists, and a CANCEL request is sent to the originating fixed IMS network to suppress or immediately stop the ringing of the call bell of the IMS terminal being investigated.

[0113] Furthermore, if the elapsed time T until the response code 183 Session Progress or 180 Ringing is received exceeds a predetermined reference time T0, it is determined that the IMS terminal linked to the telephone number being investigated is a mobile phone telephone number, and if the elapsed time T does not exceed the predetermined reference time T0, it is determined that the IMS terminal linked to the telephone number being investigated is either a data communication-only terminal, a busy terminal, or a terminal disconnected due to personal reasons.

[0114] By implementing the telephone number investigation method according to the above-mentioned flowchart, telephone numbers that are missing and telephone numbers that have been found to be telephone numbers of actual mobile phones are excluded (in other words, screened) from the list of telephone numbers to be investigated, and a telephone list (hereinafter referred to as the "limited telephone list") that requires confirmation by voice guidance, which will be explained later, is created (step S6), and stored in an appropriate memory of the telephone number investigation device 10.

[0115] Here, in the telephone number investigation method according to the present invention, the calling device (specifically, the telephone number investigation device 10) sets the telephone number to be withheld (specifically, adds "184" to the called telephone number), and then transmits the telephone number of the IMS terminal 50 to be investigated. As a result, when at least one of the anonymous call rejection service and anonymous call rejection function is set, it is possible to prevent the ringer of the IMS terminal 50 to be investigated from ringing in an investigation into the usage status of the telephone number of the IMS terminal.

[0116] The telephone number research method described below can be implemented, for example, by running a telephone number research program on a computer (specifically, telephone number research device 10) and executing the relevant procedures in accordance with the program. In telephone number research device 10, a telephone number list based on telephone numbers to be researched that are stored in telephone number history database 16 is held in an appropriate database (not shown), and the telephone number research method of this embodiment is implemented based on the telephone number list.

[0117] As SDP parameters, among the determination SDP parameters, IPv4 is described (in other words, used) for the network protocol (in other words, Internet Protocol, IP version) in the offer, and other determination SDP parameters are described as follows. The following description of the determination SDP parameters is referred to as "SDP for IPv4." ○Media type: audio only Media transport protocol: RTP / AVP only Audio Codecs: Includes G.711 μ-law and G.722

[0118] The determination made when the telephone number investigation method is carried out according to the flowchart shown in FIG. 10 will be described with reference to the general operation sequence shown in FIG.

[0119] Fig. 11 is a diagram illustrating the operation sequence when the setting to reject incoming calls is not made when the caller has set the phone number to be withheld. That is, Fig. 11 is a diagram illustrating the operation sequence when the method for investigating phone numbers of this embodiment is implemented when the anonymous call rejection service and anonymous call rejection function are not set.

[0120] The message exchange control unit 12 of the telephone number investigation device 10 transmits (F1, F2) an INVITE request addressed to the IMS terminal 50 to be investigated via the originating fixed IMS network 20 and via the terminating mobile IMS network 30, such as the mobile telephone network of the contracted carrier of the IMS terminal 50 to be investigated (step S1 in the flowchart). At this time, the above-mentioned SDP for IPv4 is described as an SDP parameter for determination (note that the network protocol is IPv4) as an SDP parameter included in the INVITE request.

[0121] In response to this, the terminating mobile IMS network 30 returns a code 100 Trying response indicating that the request has been accepted in the SIP session to the telephone number research device 10 (specifically, the message exchange control unit 12) via the originating fixed IMS network 20 (F3, F4).

[0122] Next, a code 183 Session Progress response indicating the progress of the call in the SIP session is returned from the terminating mobile IMS network 30 to the telephone number investigation device 10 (specifically, the message exchange control unit 12) via the originating fixed IMS network 20 (F5, F6). As a result, the telephone number investigation determination unit 13 determines that the telephone number of the IMS terminal 50 being investigated exists, and the message exchange control unit 12 of the telephone number investigation device 10 transmits a CANCEL request (F7, F8), which is an instruction to terminate the SIP session, to the terminating mobile IMS network 30 via the originating fixed IMS network 20 (step S2 in the flowchart). As a result, the ringing of the call bell in the terminating IMS terminal 50 being investigated is suppressed or immediately stopped.

[0123] Here, the telephone number investigation device 10 (specifically, the message exchange control unit 12) measures the elapsed time T from when an INVITE request is sent to the IMS terminal 50 to be investigated (F1, F2) until a code 183 Session Progress response indicating the progress of the call in the SIP session is received, and determines whether or not this time exceeds the reference time T0 (set to, for example, 1.1 seconds) (step S3 of the flowchart). If the elapsed time T is equal to or greater than the reference time T0 (yes), it is determined that the telephone number sent by this INVITE exists and is a mobile phone number (step S4 of the flowchart). If the elapsed time T is less than the reference time T0 (no), it is determined that the telephone number sent by this INVITE exists but is a telephone number that cannot be determined to be a mobile phone (for example, a data communication-only terminal, a busy line, or a disconnection due to personal reasons) (step S5 of the flowchart).

[0124] Here, there may be irregular cases where a code 180 Ringing response is returned without a code 183 Session Progress response being returned, depending on the contracted carrier of the IMS terminal 50. For this reason, even when the code 180 Ringing response is received without receiving a code 183 Session Progress response (F5, F6), the telephone number investigation determination unit 13 of the telephone number investigation device 10 measures the elapsed time from when an INVITE request (F1, F2) is sent to the IMS terminal 50 to be investigated until the telephone number investigation device 10 (specifically, the message exchange control unit 12) receives the code 180 Ringing response as the above-mentioned elapsed time T, and performs the same determination as when a code 183 Session Progress response (F5, F6) is received, i.e., performs steps S3 to S5 of the above-mentioned flowchart.

[0125] In the above operation sequence, in response to the CANCEL request from the calling-side device (specifically, the telephone number research device 10), a code 200 OK response indicating that the request (specifically, the CANCEL request here) has been successfully processed in the SIP session is returned from the terminating mobile IMS network 30 to the telephone number research device 10 (specifically, the message exchange control unit 12) via the originating fixed IMS network 20 (F9, F10), and a code 487 Request Terminated response indicating the cancellation of the request (in other words, the end of the session) is returned in the SIP session (F11, F12). Furthermore, the message exchange control unit 12 of the telephone number research device 10 returns an ACK (Acknowledgment) response indicating an acknowledgment in the SIP session to the terminating mobile IMS network 30 via the originating fixed IMS network 20 (F13, F14). This ends the session between the telephone number research device 10 and the terminating-side IMS terminal 50 being researched.

[0126] As can be seen from the basic sequence explained based on Figures 2 to 8, the above-mentioned operational sequence is expected to give different responses depending on the contracted carrier, the contracted business, and even whether the telephone number being investigated is a mobile phone or a data communication terminal. However, the processes shown in S2 to S5 of the flowchart above are equally applicable to any of the basic sequences, and explanations of responses related to the telephone number investigation method of this embodiment corresponding to other basic sequences will be omitted.

[0127] By carrying out steps S2 to S5 of the above flowchart, it becomes possible to register the determination results in a telephone number list (hereinafter referred to as the "limited telephone number list") that has been narrowed down to telephone numbers that require confirmation by voice guidance, which will be explained later, from the telephone number list to be investigated, excluding (in other words, screening) telephone numbers that have been found to be telephone numbers of actual mobile phones, and to create the limited telephone number list. This limited telephone number list is saved in an appropriate memory of the telephone number investigation device 10.

[0128] Next, we will explain the operation sequence when an offer is made by describing IPv4 as the network protocol and the above-mentioned SDP for IPv4 as the SDP parameter for determination, and the IMS terminal 50 to be investigated (in other words, the telephone number) is missing, with reference to the basic sequence shown in Figure 7.

[0129] When the telephone number investigation method is performed based on the above-described flowchart, in step S1, the message exchange control unit 12 of the telephone number investigation device 10 sends an INVITE request to the IMS terminal 50 to be investigated via the originating fixed IMS network 20 and then via the terminating mobile IMS network 30, such as a mobile phone network of the contracted carrier of the IMS terminal 50 to be investigated (F1, F2). At this time, as an SDP parameter included in the INVITE request, the above-described SDP for IPv4 is described for the determination SDP parameter (note that the network protocol is IPv4).

[0130] In response to this, the terminating mobile IMS network 30 returns a code 100 Trying response indicating that the request has been accepted in the SIP session to the telephone number research device 10 (specifically, the message exchange control unit 12) via the originating fixed IMS network 20 (F3, F4).

[0131] Next, a code 404 Not Found response indicating that the media resource requested by the calling party in the SIP session cannot be found is returned (F5, F6) from the called mobile IMS network 30 to the telephone number research device 10 (specifically, the message exchange control unit 12) via the calling fixed IMS network 20. In other words, if the telephone number is an unused number, neither a code 183 Session Progress nor a code 180 Ringing is returned.

[0132] 10, the determination in this case is omitted, but the telephone number investigation determination unit 13 of the telephone number investigation device 10 determines that the IMS terminal 50 to be investigated on the called party is an unused number (i.e., the telephone number of the IMS terminal 50 to be investigated is an unused number) based on the returned code 404 Not Found response. Note that an unused number also includes a case where the IMS terminal 50 to be investigated on the called party has been canceled. If the telephone number to be investigated is an unused number, steps S2 and subsequent steps in the flowchart are not performed.

[0133] Next, the message exchange control unit 12 of the telephone number research device 10 returns an ACK (Acknowledgment) response indicating an acknowledgment in the SIP session to the terminating mobile IMS network 30 via the originating fixed IMS network 20 (F7, F8). This ends the session related to the INVITE request from the telephone number research device 10, and records in the telephone number history database 16 in the telephone number research device 10 that the telephone number being researched is a missing number. In such a case, the above-described flowchart ends without proceeding to step S2 or later.

[0134] The above-described telephone number investigation method is implemented, for example, by a program set in telephone number investigation device 10 that satisfies the following requirements.

[0135] The present invention is directed to a method for making a computer (telephone number investigation device 10) connected to a plurality of IMS terminals 50 connected to a terminating mobile IMS network 30 via an originating fixed IMS network 20 at least perform the following processes: assigning SDP parameters to an INVITE request for the IMS terminal 50 to be investigated and transmitting the INVITE request to the originating fixed IMS network 20; receiving a response message via the originating fixed IMS network 20; and determining the usage status of the telephone number of the IMS terminal 50 to be investigated according to the response message; the SDP parameters describing a network protocol of IPv4, a media type of audio only, a media transport protocol of RTP / AVP only, and voice codecs including G.711μ-law and G.722, and simultaneously offering G.711μ-law and G.722 as the voice codecs, thereby enabling a response from the terminating side when the IMS terminal 50 to be investigated is an unused number to be returned as code 404 Not and when only G.711 μ-law is offered as the voice codec, if the response from the terminating side in the case where the IMS terminal to be investigated actually exists is code 183 Session Progress or 180 Ringing, determine that the telephone number of the IMS terminal to be investigated actually exists, and by transmitting a CANCEL request to the originating fixed IMS network 20, the CANCEL request is transmitted to the terminating mobile IMS network 30 via the originating fixed IMS network 20, and execute processing to suppress or immediately stop ringing of the call bell of the IMS terminal to be investigated; if the elapsed time T until the response with code 183 Session Progress or 180 Ringing is received exceeds a predetermined reference time T0, determine that the IMS terminal 50 linked to the telephone number to be investigated is a mobile phone; and if the elapsed time T does not exceed the predetermined reference time T0, determine that the IMS terminal 50 linked to the telephone number to be investigated is any of a data communication-only terminal, a busy terminal, or a temporary disconnection.

[0136] The investigation program further includes a program for executing the following processes: a process for determining the usage status of the telephone number of the IMS terminal 50, and a process for creating a telephone number list excluding telephone numbers of terminals determined to be mobile phones from the investigation targets, based on the telephone number of the IMS terminal 50 linked to the telephone number of the investigation target determined to be any of a data communication-only terminal, a busy terminal, and a temporary disconnection; a process for executing the message exchange control unit 12 and the telephone number investigation determination unit 13 based on the telephone number list to determine the usage status of the telephone number of the IMS terminal 50 to be investigated, and a process for extracting an audio file from the audio guidance after receiving the response code 183 Session Progress or 180 Ringing by the voice conversion unit 15, and creating text data based on the audio file; and a process for determining, based on the text data, that the telephone number of the investigation target corresponds to any of a data communication-only terminal, a busy terminal, and a temporary disconnection.

[0137] According to the telephone number research method of the present embodiment and the telephone number research program for implementing the telephone number research method, it is possible to create the restricted telephone number list by excluding (screening) telephone numbers that can be determined to be real and mobile phone telephone numbers, and telephone numbers that have been determined to be missing numbers, from the list of telephone numbers to be researched. In other words, it is possible to create the restricted telephone number list by extracting telephone numbers that need to be determined as telephone numbers by analyzing voice guidance such as data communication-only terminal, temporary disconnection, busy, etc. from the list of telephone numbers to be researched.

[0138] Once the limited telephone number list has been created as described above, the telephone number to be investigated that is registered in the limited telephone number list is obtained by the voice guidance call control server disposed in the voice conversion unit 15 of the telephone number investigation device 10, and an INVITE request is sent to the IMS terminal 50 to be investigated according to the operation sequence described above. Then, the telephone number investigation device 10 (specifically, the message exchange control unit 12) receives a code 183 Session Progress response (or a code 180 Ringing response) indicating the progress of the call in the SIP session. Here, if the telephone number to be investigated was busy in the investigation method based on the flowchart described above, the busy status may be released. In this case, the elapsed time T may exceed the reference time T0 (e.g., 1.1 seconds). Therefore, even when an INVITE request is sent to the IMS terminal 50 to be investigated based on the limited telephone number list, the time T elapsed from the time the INVITE request is sent until the time a code 183 Session Progress response (or a code 180 Ringing response) is received may be measured, and if this elapsed time T exceeds the reference time T0, the telephone number to be investigated may be determined to be a mobile telephone number, and a CANCEL request may be sent to the originating fixed IMS network at that point. This allows the usage status of the telephone number to be investigated to be confirmed without analyzing the voice guidance, and the ringing of the call bell may be suppressed or immediately stopped, thereby terminating the operation sequence.

[0139] If the elapsed time T for a telephone number extracted from the limited telephone number list does not exceed the reference time T0, the voice conversion unit 15 in the telephone number research device 10 receives voice guidance as a reply in accordance with the response shown in the basic sequence described above with reference to Figures 4 to 6.

[0140] As described above, the voice conversion unit 15 includes a call control server for voice guidance that records (in other words, captures packets) the voice guidance and stores it as voice data, and when a code 183 Session Progress response is returned following the voice guidance, stores the recorded and stored voice data in a memory or storage device.The voice conversion unit 15 also includes a voice recognition unit (not shown) that converts the voice data stored in the call control server for voice guidance into text (i.e., Speech to Text) and stores the converted text data in a memory or storage device (neither of which are shown).

[0141] The text data is then analyzed by the telephone number investigation determination unit 13 to determine whether the IMS terminal 50 being investigated is a dedicated data communication terminal, is busy, is disconnected due to personal reasons, or the like.

[0142] The analysis of the text data is performed based on, for example, the names of the contracted carriers and contracted businesses included in the text data, and typical words included in the response message. For example, the determination is performed as follows:

[0143] If the telephone number being surveyed is linked to a data communication-only terminal, the voice guidance will be, for example, as follows: "This is AAA (your contract carrier name)... The number you have dialed is for data communication only..." By analyzing such text data, it is possible to easily determine that the telephone number being investigated is a data communication-only terminal.

[0144] Furthermore, when the telephone number to be investigated is in a state of being removed due to personal reasons, the voice guidance is, for example, as follows: "This is BBB (your contracted carrier name)... We are unable to connect the number you have dialed due to customer circumstances..." By analyzing such text data, it is possible to easily determine whether the telephone number being investigated is currently unavailable.

[0145] Furthermore, if the telephone number being investigated is busy, as explained based on the basic sequence shown in Figure 6, the receiving device will send out a busy tone indicating that the number is busy.Therefore, the busy tone stored in the voice guidance call control server can be saved as voice data and analyzed to determine whether the number is busy.

[0146] As described above, by converting the voice guidance data obtained when an INVITE signal is sent to the telephone number to be investigated into text and analyzing it, it is possible to easily determine whether the telephone number to be investigated is a data communication-only terminal, is disconnected due to personal reasons, or is busy. Note that depending on the contracted carrier or contracted business, there may be differences in the message, such as not including the name of the responding contracted carrier in the reply voice guidance. In such cases, by setting specific words in the text data of the voice guidance and analyzing the text data, it is possible to determine whether the telephone number to be investigated is a data communication-only terminal, is disconnected due to personal reasons, or is busy.

[0147] As described above, a timestamp indicating the date and time of the determination is assigned to each determination result by the telephone number investigation determination unit 13 based on the text data, and these are recorded in chronological order on the recording medium of the telephone number history database 16, thereby constructing and updating data relating to the history of the usage status of the telephone number being investigated.

[0148] According to the telephone number investigation method of this embodiment, it is possible to create a telephone number list (limited telephone number list) in which telephone numbers for which voice guidance does not need to be analyzed are excluded (screened) from the list of telephone numbers to be investigated in order to check the usage status of the telephone number to be investigated, thereby significantly reducing the time required to check the usage status of all telephone numbers to be investigated.Furthermore, by implementing the telephone number investigation method based on the limited telephone number list, a judgment is made based on the voice guidance, and it is possible to determine whether the telephone number to be investigated is a data communication-only terminal, is in a temporary disconnected state, or is busy.

[0149] Figure 12 shows a summary of a method for investigating the usage status (specifically, whether it is a mobile phone, a data communication-only terminal, an unused number, busy, or disconnected for personal reasons, etc.) of the telephone number of the IMS terminal 50 (specifically, for example, the telephone number of a mobile phone with a 0A0 type telephone number or a data communication-only terminal) based on the above-mentioned operation sequence.

[0150] The usage status of the telephone numbers of mobile phones and data communication-only terminals with 0A0 type (specifically, for example, 090, 080, and 070) telephone numbers of IMS terminals 50 connected to a telecommunications operator (in other words, a telecommunications carrier) can be accurately determined by describing IPv4 as the network protocol (in other words, Internet Protocol, IP version) among the SDP parameters, making an SDP offer (i.e., an INVITE request) using SDP for IPv4 for other SDP parameters, and implementing the telephone number investigation method described above.

[0151] (Phone number investigation program) As an example of a specific configuration of the telephone number research program according to the present invention, the telephone number research program according to the embodiment is a program implemented in a telephone number research device 10 (see Figure 9) connected to a plurality of IMS terminals 50 connected to a destination mobile IMS network 30 via a destination fixed IMS network 20.

[0152] The telephone number investigation program according to the embodiment causes a computer (specifically, a telephone number investigation device 10) connected to a plurality of IMS terminals 50 connected to a terminating mobile IMS network 30 via an originating fixed IMS network 20 to perform at least the following processes: adding SDP parameters to an INVITE request for the IMS terminal 50 being investigated and transmitting the INVITE request to the originating fixed IMS network 20 (toward the IMS terminal 50 being investigated); receiving a response message via the originating fixed IMS network 20; and determining the usage status of the telephone number of the IMS terminal 50 being investigated based on the response message.

[0153] The telephone number investigation program according to the embodiment is configured such that the SDP parameters are described such that the network protocol is IPv4, the media type is audio only, the media transport protocol is RTP / AVP only, and the audio codec includes G.711μ-law and G.722 (i.e., SDP for IPv4). In this way, the telephone number investigation program according to the present embodiment implements the telephone number investigation method described above, and the above-mentioned operational effects can be obtained.

[0154] (Telephone number information system) FIG. 13 is a system configuration diagram of a telephone number information providing system 100 as an example of the configuration of a telephone number information providing system realized using the telephone number research method of this embodiment.

[0155] The telephone number information provision system 100 in the illustrated embodiment includes one or more user terminals 90, and a telephone number research server (specifically, a telephone number research device 10) connected to the user terminals 90 via an IP network 80 and also connected to a network not shown (for example, a calling fixed IMS network 20).

[0156] The telephone number information provision system 100 according to the illustrated embodiment has a telephone number investigation server (specifically, telephone number investigation device 10) and a user terminal 90, and is provided with a network interface unit 11 that, when the telephone number investigation server (specifically, telephone number investigation device 10) receives a telephone number investigation information provision request for an IMS terminal 50 from the user terminal 90, transmits the telephone number usage status of the IMS terminal 50 determined by the telephone number investigation determination unit 13 to the user terminal 90 that has made the telephone number investigation information provision request via an IP network 80 (see FIG. 9).

[0157] When the telephone number investigation server (specifically, the telephone number investigation device 10) receives a request for telephone number investigation information regarding the telephone number to be investigated from the user terminal 90 via the IP network 80, it refers to a recording medium (specifically, the telephone number history database 16, in this case recorded on a DVD) in which information regarding the telephone number usage status is stored, with a timestamp indicating the date and time of the determination being assigned to each of the usage status determination results obtained by implementing the telephone number investigation method described above, and transmits the information regarding the telephone number usage status via the IP network 80 to the user terminal 90 that made the telephone number investigation information request, based on the usage status determination results obtained by the telephone number investigation method described above.

[0158] The recording medium storing information related to the usage of telephone numbers (specifically, telephone number history database 16) may be distributed independently (for example, on a DVD) to users who require it. The recording medium storing information related to the usage of telephone numbers (telephone number history database 16) may be generated by telephone number investigation device 10 connected to a telecommunications carrier network via a dedicated line, for example, and is a recording medium that records whether or not the telephone number being investigated actually exists, and may be used for search in the system to which it is distributed.

[0159] The recording medium (specifically, telephone number history database 16) storing information related to the usage status of telephone numbers is a collection of results of validity judgments on the usage status of telephone numbers of the receiving party's telephone terminal (specifically, a mobile phone or a dedicated data communication terminal as an IMS terminal 50), and for example, each judgment result is assigned a timestamp indicating the date and time of the judgment and is recorded in chronological order.

[0160] The distribution of recording media (specifically, telephone number history database 16) storing information related to telephone number usage is not limited to distribution in the form of a database recorded on a DVD or hard disk, but also includes distribution using a communication line. [Explanation of symbols]

[0161] 10: Telephone number investigation device 11: Network interface unit 12: Message exchange control section 13: Telephone number investigation judgment unit 14: Phone number history generation unit 15: Voice conversion unit 16: Phone number history database 20: Originating fixed IMS network 20a: SIP server 21:Originating IBCF 30: Destination mobile IMS network 30a: SIP server 30b: SIP server 30c: SIP server 31: Terminating IBCF 50, 50a, 50b, 50c: IMS terminal 90: User terminal 100: Information provision system

Claims

1. A telephone number research device connected to a plurality of IMS terminals connected to a destination mobile IMS network via a source fixed IMS network, a message exchange control unit that adds SDP parameters to an INVITE request addressed to the IMS terminal to be investigated, transmits the INVITE request to the originating fixed IMS network, and receives a response message via the originating fixed IMS network; a telephone number investigation determination unit that determines the usage status of the telephone number of the IMS terminal that is the investigation target in accordance with the response message, The SDP parameters are described as including a network protocol of IPv4, a media type of audio only, a media transport protocol of RTP / AVP only, and an audio codec of G.711 μ-law and G.722; By simultaneously offering G.711 μ-law and G.722 for the voice codec, the response from the terminating side when the IMS terminal being investigated is an unused number is made to be code 404 Not Found, and when only G.711 μ-law is offered for the voice codec and the response from the terminating side when the IMS terminal being investigated actually exists is code 183 Session Progress or 180 Ringing, the telephone number investigation determination unit determines that the telephone number of the IMS terminal being investigated actually exists, and the message exchange control unit transmits a CANCEL request to the originating fixed IMS network, thereby suppressing the ringing of the IMS terminal being investigated, If the elapsed time until the code 183 Session Progress or 180 Ringing response is received exceeds a predetermined reference time, the IMS terminal linked to the telephone number being investigated is determined to be a mobile phone that does not require analysis by voice guidance of the RTP received after receiving the code 183 Session Progress response or the code 180 Ringing response, and if the elapsed time does not exceed the predetermined reference time, the IMS terminal linked to the telephone number being investigated is determined to be either a data communication-only terminal that requires analysis by voice guidance of the RTP, a busy line, or a temporary disconnection, and the telephone number investigation device creates a telephone number list excluding telephone numbers of terminals that are determined to be mobile phones from the investigation targets, based on telephone numbers of investigation targets whose IMS terminal linked to the telephone number being investigated is determined to be either a data communication-only terminal, a busy line, or a temporary disconnection.

2. In addition to the above configuration, a voice conversion unit is provided, The investigation device according to claim 1, wherein the message exchange control unit and the telephone number investigation determination unit are executed based on the telephone number list to determine the usage status of the telephone number of the IMS terminal being investigated, the voice conversion unit extracts an audio file from the voice guidance after receiving a response with the code 183 Session Progress or 180 Ringing, creates text data based on the audio file, and determines based on the text data whether the telephone number being investigated corresponds to a data communication-only terminal, a busy line, or a disconnection due to personal reasons.

3. A telephone number investigation method for investigating the usage status of telephone numbers of IMS terminals to be investigated using a device connected to a plurality of IMS terminals connected to a terminating mobile IMS network via an originating fixed IMS network, comprising: The device, adding SDP parameters to an INVITE request addressed to the IMS terminal to be investigated, and transmitting the INVITE request to the originating fixed IMS network; receiving a response message via the originating fixed IMS network; determining the usage status of the telephone number of the IMS terminal being investigated in response to the response message; The SDP parameters are described as including a network protocol of IPv4, a media type of audio only, a media transport protocol of RTP / AVP only, and an audio codec of G.711 μ-law and G.722; By simultaneously offering G.711μ-law and G.722 for the voice codec, the response from the terminating side when the IMS terminal being investigated is an unused number is code 404 Not Found, and when only G.711μ-law is offered for the voice codec and the response from the terminating side when the IMS terminal being investigated actually exists is code 183 Session Progress or 180 Ringing, the telephone number of the IMS terminal being investigated is determined to be actual, and a CANCEL request is sent to the originating fixed IMS network, thereby suppressing the ringing of the IMS terminal being investigated, If the time elapsed until the response of the code 183 Session Progress or the code 180 Ringing is received exceeds a predetermined reference time, the IMS terminal linked to the telephone number being investigated is determined to be a mobile phone that does not require analysis by the voice guidance received after receiving the response of the code 183 Session Progress or the code 180 Ringing, and if the time elapsed does not exceed a predetermined reference time, the IMS terminal linked to the telephone number being investigated is determined to be either a data communication-only terminal that requires analysis by the voice guidance, a busy terminal, or a terminal disconnected due to personal reasons, A method for investigating telephone numbers, which includes a step of determining the usage status of the telephone number of the IMS terminal, and a step of creating a telephone number list excluding telephone numbers of terminals determined to be mobile phones from the investigation target, based on the telephone number of the investigation target telephone number determined to be a data communication-only terminal, busy, or disconnected for personal reasons.

4. The device includes: a message exchange control unit that adds SDP parameters to an INVITE request to the IMS terminal under investigation, sends the INVITE request to the originating fixed IMS network, and receives a response message via the originating fixed IMS network; a telephone number investigation determination unit that determines the usage status of the telephone number of the IMS terminal that is the investigation target in accordance with the response message; and a voice conversion unit; Executing the message exchange control unit and the telephone number investigation determination unit based on the telephone number list to determine the usage status of the telephone number of the IMS terminal to be investigated, and extracting a voice file from the voice guidance after receiving the response of the code 183 Session Progress or 180 Ringing by the voice conversion unit, and creating text data based on the voice file; 4. The method for investigating telephone numbers according to claim 3, further comprising a step of determining, based on the text data, whether the telephone number being investigated corresponds to a data communication-only terminal, a busy line, or a disconnection due to personal reasons.

5. A computer connected to a plurality of IMS terminals connected to a terminating mobile IMS network via an originating fixed IMS network, a process of adding an SDP parameter to an INVITE request addressed to the IMS terminal to be investigated and transmitting the INVITE request to the originating fixed IMS network; receiving a response message via the originating fixed IMS network; and determining the usage status of the telephone number of the IMS terminal to be investigated in response to the response message; The SDP parameters are: network protocol is IPv4, media type is audio only, media transport protocol is RTP / AVP only, and audio codec is G.711 It is described as including μ-law and G.722, Regarding the audio codec, G.711 By simultaneously offering μ-law and G.722, the response from the terminating side when the IMS terminal to be investigated is an unused number is made to be code 404 Not Found, and when only G.711 μ-law is offered for the voice codec and the response from the terminating side when the IMS terminal to be investigated actually exists is code 183 Session Progress or 180 Ringing, the telephone number of the IMS terminal to be investigated is determined to be actual, and a CANCEL request is sent to the originating fixed IMS network, thereby executing a process to suppress ringing of the call bell of the IMS terminal to be investigated, A telephone number investigation program that performs a process of: if the elapsed time until the code 183 Session Progress or 180 Ringing response is received exceeds a predetermined reference time, determining that the IMS terminal linked to the telephone number being investigated is a mobile phone that does not require analysis by voice guidance received after receiving the code 183 Session Progress response or the code 180 Ringing response; if the elapsed time does not exceed a predetermined reference time, determining that the IMS terminal linked to the telephone number being investigated is either a data communication-only terminal that requires analysis by voice guidance, a busy line, or a personal disconnection; and determining the usage status of the telephone number of the IMS terminal, and creating a telephone number list excluding telephone numbers of terminals determined to be mobile phones from the investigation targets, based on telephone numbers being investigated that are determined to be either a data communication-only terminal, a busy line, or a personal disconnection, by a process of determining the usage status of the telephone number of the IMS terminal.

6. The computer includes a message exchange control unit that adds SDP parameters to an INVITE request for the IMS terminal under investigation and sends the INVITE request to the originating fixed IMS network, and receives a response message via the originating fixed IMS network; a telephone number investigation determination unit that determines the usage status of the telephone number of the IMS terminal under investigation according to the response message; and a voice conversion unit; a process of executing the message exchange control unit and the telephone number investigation determination unit based on the telephone number list to determine the usage status of the telephone number of the IMS terminal to be investigated, and extracting an audio file from the audio guidance after receiving the response of the code 183 Session Progress or 180 Ringing by the voice conversion unit, and creating text data based on the audio file; 6. The telephone number investigation program according to claim 5, further comprising a process for determining, based on the text data, whether the telephone number to be investigated corresponds to a data communication-only terminal, a busy line, or a temporary disconnection.

Images