JP2008085821A - Incoming call forwarding method and incoming call forwarding system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transmit mutual terminal information when terminals connected to a circuit switching network transmit and receive bit stream through a packet exchange network. <P>SOLUTION: The terminal is a 3G-324M terminal of a 3GPP standard, and the bit stream is H. 223 recommended by ITU-T. A gateway which forwards the bit stream from a circuit switching network to a packet exchange network, divides the H. 223 bit stream received from the circuit switching network into specified lengths, and forwards it to the packet exchange network after changing it to a UDP packet. A gateway which forwards the bit stream from the packet exchange network to the circuit switching network receives the H. 223 bit stream having been changed to the UDP packet from the packet exchange network, and forwards the H. 223 bit stream that has been taken out of the UDP packet to the circuit switching network. The H. 223 bit stream can be divided for each MUX-PDU. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention enables packet exchange between terminals connected to a circuit switching network via a gateway that transfers a bit stream from the circuit switching network to the packet switching network and a gateway that transfers a bit stream from the packet switching network to the circuit switching network. The present invention relates to an incoming call transfer method for transmitting and receiving a bit stream via a network and an incoming call transfer system thereof.

  In recent years, bidirectional communication systems that transmit and receive audio and video encoded data in packets via an IP network have become widespread. In addition to such a communication system between multimedia terminals on a packet switching network, multimedia terminals capable of making a videophone call on a circuit switching network have been released and are becoming widespread.

  Multimedia terminals on packet-switched networks and multimedia terminals on circuit-switched networks have different protocols. By introducing a gateway to absorb these protocol differences, multimedia terminals on packet-switched networks It is possible to communicate with multimedia terminals on a circuit switched network without being aware of the difference in protocols.

  Here, in the network service (incoming call transfer) for transferring the incoming call from the caller, when the multimedia terminal on the packet switching network and the multimedia terminal on the circuit switching network become communicable in this way, A transfer method in which a call originating from a multimedia terminal on the switching network and arriving at the multimedia terminal on the packet switching network is transferred to another multimedia terminal on the circuit switching network is conceivable.

  In the case of the connection method by the above-mentioned circuit switching network → packet switching network → circuit switching network incoming transfer, the gateway that transfers the bit stream from the circuit switching network to the packet switching network, and the bit stream from the packet switching network to the circuit switching network The multimedia terminals connected to the circuit switching network transmit / receive a bit stream via the packet switching network via the gateway for transferring the data.

Re-specialized WO20 / 017637 JP 2003-230117 A JP 2003-298676 A JP 2004-214755 A

  However, the gateway located at the relay point between the circuit switching network and the packet switching network terminates the bit stream transmitted from the multimedia terminal connected to the circuit switching network. Information about the terminal cannot be transmitted to the multimedia terminal on the other circuit switched network.

H. In the conventional system configuration. 245 negotiation will be described with reference to FIG. Here, the bit stream transfer from the 3G-324M terminal 1 to the 3G-324M terminal 7 will be described.
(1) The 3G-324M terminal 1 connected on the circuit switching network 2 is connected to the gateway 300 with H.264. Conduct 245 negotiations. This H. When conducting the H.245 negotiation, The H.223 demultiplexing unit 302 receives the H.264 received from the 3G-324M terminal 1 via the circuit switching network 2. By separating the 223 bitstream, Retrieve the 245 message. H. In the H.245 processing unit 301, H.264 processing is performed. H.223 demultiplexing unit 302 extracts H.264. Decrypts the H.245 message.
(2) The gateway 300 is connected to the H.264 gateway. After the H.245 negotiation, the H.264 received from the 3G-324M terminal 1 via the circuit switching network 2 is used. The audio and video bitstreams are extracted by separating the 223 bitstream and transferred to the gateway 500.
(3) The gateway 500 communicates with the 3G-324M terminal 7 connected on the circuit switching network 6 as described in (1) above. Conduct 245 negotiations. H. After performing the H.245 negotiation, the audio and video bit stream received from the gateway 300 via the packet switching network 4 is converted into the H.264 format. The data is transferred to the 3G-324M terminal 7 by multiplexing on the 223-bit stream.

  In the procedure (2), the H.264 between the gateways 300 and 500 is determined. 245 negotiation is not performed. H. In the H.245 negotiation, what kind of capability (codec or the like) the communication partners have in advance with each other, what kind of multiplexing table is used in the H.245 negotiation. What is the audio or video encoding method or encoding information (for example, MPEG-4 bit stream encoding (DCI: Decoder Configuration Information) information) when multiplexing 223-bit streams or performing communication? The information is not transmitted between the gateway 300 and the gateway 500 in the step (2). As a result, the terminal information cannot be exchanged between the 3G-324M terminal 1 and the 3G-324M terminal 7.

  Therefore, even if terminals connected to the circuit switching network can transmit and receive a bit stream via the packet switching network, the terminals need to acquire terminal information separately by some method in advance. This is extremely troublesome for the user. In addition, if there is no method for mutually acquiring terminal information in advance, transmission / reception of a bit stream cannot be substantially performed.

  The present invention has been performed under such a background, and when terminals connected to different circuit switched networks transmit / receive a bit stream via the packet switched network, the terminal information of each other is transmitted. An object of the present invention is to provide a call transfer method and a call transfer system that can communicate with each other.

  The present invention relates to a terminal connected to a circuit switching network via at least one gateway for transferring a bit stream from the circuit switching network to the packet switching network and at least one gateway for transferring the bit stream from the packet switching network to the circuit switching network. This is an incoming transfer method in which a bit stream is transmitted and received via a packet switching network.

  Here, a feature of the present invention is that the terminal is a 3G-324M terminal of the 3GPP standard, and the bit stream is ITU-T recommendation H.264. 223, and the gateway that transfers the bit stream from the circuit switching network to the packet switching network receives the H.264 received from the circuit switching network. The gateway that divides the 223 bit stream into predetermined lengths, converts the packet into a UDP (User Datagram Protocol) packet, transfers the packet to the packet switching network, and transfers the bit stream from the packet switching network to the circuit switching network. From UDP packetized from UDP. A H.223 bit stream is received and extracted from this UDP packet. 223 bit stream is transferred to the circuit switched network.

  That is, in the present invention, H.264 between the 3G-324M terminal and the gateway is used. H.245 negotiation is not performed, and the gateway does not perform H.245 negotiation. By transferring the 223-bit stream as a UDP packet without separation or multiplexing, the H.323 bit stream is directly transmitted between 3G-324M terminals. 245 negotiation is performed.

  Moreover, instead of dividing into the predetermined length, H. It is also possible to divide each MUX-PDU (Multiplex-Protocol Data Unit), which is a constituent unit of a 223-bit stream.

  That is, H.I. Since the MUX-PDU, which is a constituent unit of the 223-bit stream, has a variable length, When a 223-bit stream is divided by a predetermined length, one MUX-PDU may be divided in the middle. In order to avoid such a situation, it is desirable to divide each MUX-PDU.

  Further, each of the divided individual H.P. If an RTP header is added to each 223-bit stream, each divided H.264 file is referred to by referring to an RTP (Real-time Transport Protocol) header. Even when the order of the 223-bit stream is reversed and arrives at the other gateway, this can be compensated.

  An incoming call transfer system of the present invention that realizes such an incoming call transfer method of the present invention includes a gateway that transfers a bit stream from a circuit switched network to a packet switched network, and a gateway that transfers a bit stream from the packet switched network to the circuit switched network. The terminal connected to the circuit switched network transmits and receives a bit stream to and from a terminal connected to a different circuit switched network via the packet switched network through at least one gateway. Means.

  Here, a feature of the present invention is that the terminal is a 3G-324M terminal of the 3GPP standard, and the bit stream is ITU-T recommendation H.264. 223, and the gateway receives the H.264 received from the circuit switched network. Means for dividing a 223-bit stream into a predetermined length, converting it into a UDP packet and transferring it to the packet switching network; A H.223 bit stream is received and extracted from this UDP packet. Means for transferring a 223 bit stream to the circuit switched network.

  In addition, the gateway may be replaced with H.264 instead of dividing into the predetermined length. It is also possible to provide means for dividing each MUX-PDU, which is a structural unit of the 223-bit stream. In addition, the gateway is configured such that the divided individual H.264 Means for attaching an RTP header to each of the 223-bit streams may be provided.

  The present invention can also be viewed from the gateway perspective. That is, the present invention is a gateway for transferring a bit stream between a circuit switched network and a packet switched network, and the present invention is characterized by the 3GPP standard 3G-324M connected to the circuit switched network. ITU-T recommendation H.264 received from the terminal. Means for dividing a 223-bit stream into a predetermined length, converting it into a UDP packet and transferring it to the packet switching network; A H.223 bit stream is received and extracted from this UDP packet. Means for transferring a 223 bit stream to the circuit switched network.

  Moreover, instead of dividing into the predetermined length, H. It is also possible to provide means for dividing each MUX-PDU, which is a structural unit of the 223-bit stream. Further, each of the divided individual H.P. Means for attaching an RTP header to each of the 223-bit streams may be provided.

  The present invention can also be viewed from the viewpoint of a program. That is, the present invention is a program that, when installed in a general-purpose information processing apparatus, causes the general-purpose information processing apparatus to realize a function corresponding to the function of the gateway of the present invention.

  By recording the program of the present invention on a recording medium, the general-purpose information processing apparatus can install the program of the present invention using this recording medium. Alternatively, the program of the present invention can be directly installed on the general-purpose information processing apparatus via a network from a server that holds the program of the present invention.

  Thereby, the gateway of this invention is realizable using a general purpose information processing apparatus. The program of the present invention includes not only a program that can be directly executed by a general-purpose information processing apparatus but also a program that can be executed by installing it on a hard disk or the like. Also included are those that are compressed or encrypted.

  In accordance with the present invention, H.264 between 3G-324M terminals. By performing the H.245 negotiation, the terminal information of one 3G-324M terminal can be transmitted to the other 3G-324M terminal. Further, according to the present invention, it is possible to rearrange the packets in the normal packet order by referring to the sequence number of the RTP header of the received packet.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 shows an entire incoming call transfer system including an incoming call transfer method according to the present invention. The gateway 3 is installed at a relay point when the circuit switching network 2 and the packet switching network 4 are connected, and the gateway 5 is arranged at a relay point when connecting the packet switching network 4 and the circuit switching network 6, and circuit switching is performed. The 3G-324M terminal 1 connected to the network 2 and the 3G-324M terminal 7 connected to the circuit switching network 6 are connected to the H.264 network via the packet switching network 4. The 223-bit stream is transmitted / received.

(First Example)
A first embodiment of the present invention will be described with reference to FIG. 1, FIG. 2, and FIG. FIG. 2 and FIG. 3 show a principal block configuration of the gateways 3 and 5 in the first embodiment. H. The transfer direction of the 223-bit stream can be bidirectional, but here, the transfer direction from the 3G-324M terminal 1 to the 3G-324M terminal 7 will be described for easy understanding.

  In the 3G-324M terminal 1, the H.264 H.245 for negotiation. H.245 message. Multiplex on a 223-bit stream for transmission.

  H. of gateway 3 The 223-bit stream reception processing unit 10 receives the H.264 signal from the circuit switching network 2. H.245 message multiplexed. A 223-bit stream is received. H. The 223-bit stream division processing unit 11 H.223 received by the 223-bit stream reception processing unit 10. The 223-bit stream is divided into predetermined lengths. H. The 223-bit stream packetizing processing unit 12 H.264 divided by the 223-bit stream division processing unit 11. The 223-bit stream is converted into a UDP packet.

  H. H.264 divided by the 223-bit stream division processing unit 11. H.223 bit stream. What is packetized by adding a UDP / IP header in the 223-bit stream packetization processing unit 12 is hereinafter referred to as H.264. It will be called 223 packets.

  H. The H.223 packet transmission processing unit 13 receives the H.264 packet transmission process. H.223 bit stream packetized by the 223 bit stream packetization processing unit 12. 223 packets are transmitted to the packet switching network 4.

  H. of gateway 5 The H.223 packet reception processing unit 20 receives the H.264 packet from the packet switching network 4. 223 packets are received. H. The 223-bit stream extraction processing unit 21 receives the H.264 bit stream. 223 received by the H.223 packet reception processing unit 20. 223 packets to H.264 Extract the 223-bit stream. H. The 223-bit stream combination processing unit 22 H.223 extracted by the 223-bit stream extraction processing unit 21. Combine 223 bitstreams. H. The 223-bit stream transmission processing unit 23 is the H.264 H.223 bit stream combining processing unit 22 combined with H.223. A 223-bit stream is transmitted to the circuit switching network 6.

  The 3G-324M terminal 7 is connected to the H.264 from the circuit switching network 6. H.245 message multiplexed. 223 bit stream is received. By separating the 223-bit stream, the H.264 transmission from the 3G-324M terminal 1 is performed. Decrypts the H.245 message.

  Up to this point, the H.323 for the direction from the 3G-324M terminal 1 to the 3G-324M terminal 7 is described. Although the flow of the 223 bit stream has been described, in practice, the H.323 bit stream is also used in the direction from the 3G-324M terminal 7 to the 3G-324M terminal 1. 223 bit stream is transferred and H.264 is transferred. H.264 multiplexed on a 223-bit stream. The H.245 message is exchanged between the 3G-324M terminals 1 and 7 with each other so that the H.264 message is directly exchanged between the 3G-324M terminals 1 and 7. 245 negotiation can be performed.

(Second embodiment)
The second embodiment will be described with reference to FIGS. 1, 2, 3 and 4. FIG. FIG. It is a figure for demonstrating the effect by the division | segmentation for every MUX-PDU of a 223 bit stream. The second embodiment is the same method and system as the first embodiment. Hereinafter, the description of the parts common to the first embodiment will be omitted, and only the parts that are different will be described.

  H. The 223-bit stream division processing unit 11 H.223 received by the 223-bit stream reception processing unit 10. The 223-bit stream is divided for each MUX-PDU. Processing other than the above is the same as in the first embodiment.

  That is, H.I. Since the MUX-PDU, which is a constituent unit of the 223-bit stream, has a variable length, When a 223-bit stream is divided by a predetermined length, one MUX-PDU may be divided in the middle.

  In the example of FIG. 4A, the entire MUX-PDU # 1 and the middle of MUX-PDU # 2 are divided (1), and the middle of MUX-PDU # 2 to the middle of MUX-PDU # 3 are divided ( 2), and the remaining part of MUX-PDU # 3 is divided (3).

  Even in the case of such division, if these divisions (1) to (3) are transferred without omission, all the MUX-PDUs # 1 to # 3 can be normally separated at the transfer destination. However, if division (1) is lost during transfer, neither MUX-PDU # 1 nor MUX-PDU # 2 can be normally separated at the transfer destination. Similarly, when division (2) is lost during transfer, both MUX-PDU # 2 and MUX-PDU # 3 cannot be normally separated at the transfer destination.

  Therefore, as shown in FIG. 4B, by dividing each MUX-PDU, it is possible to avoid that a plurality of MUX-PDUs are affected when any one of the divisions (1) to (3) is lost. It is possible to separate normally except for the missing MUX-PDU.

(Third embodiment)
A third embodiment will be described with reference to FIGS. 1, 5, and 6. FIG. FIG. 5 and FIG. 6 show the principal block configuration of the gateways 3 and 5 in the third embodiment. The third embodiment is the same method and system as the first embodiment. Hereinafter, the description of the parts common to the first embodiment will be omitted, and only the parts that are different will be described.

  The RTP header addition processing unit 32 is an H.264 protocol. H.264 divided by the 223-bit stream division processing unit 31. An RTP header is added to the 223-bit stream. H. received from circuit switched network. Since the bandwidth of the 223-bit stream is 64 kbps, the time stamp in the RTP header provided by the RTP header addition processing unit 32 includes H.264. The H.223 bit stream division processing unit 31 divides the H.264 stream into predetermined lengths. A value corresponding to the length of the 223-bit stream is stored.

  The RTP header analysis processing unit 41 is an H.264 protocol. The RTP header is extracted from the UDP packet received by the 223 packet reception processing unit 40, and the sequence number in the extracted RTP header is analyzed. As a result of the analysis, when the exchange of the arrival order of the UDP packets is detected, the received UDP packets are rearranged so that the arrival order is correct. Processing other than the above is the same as in the first embodiment.

(Fourth embodiment)
A fourth embodiment will be described with reference to FIGS. 1, 4, 5, and 6. FIG. The fourth embodiment is the same method and system as the third embodiment. In the following, description of parts common to the third embodiment will be omitted, and only different parts will be described.

  H. The 223-bit stream segmentation processing unit 31 The H.223 bit stream reception processing unit 30 receives the H.264 signal. The 223-bit stream is divided for each MUX-PDU. Processing other than the above is the same as in the third embodiment. H. The effect of dividing the 223-bit stream for each MUX-PDU is as described with reference to FIG. 4 in the second embodiment.

  In the embodiment described so far, the configuration in which the gateways 3 and 5 are used one by one has been described. However, in the present invention, the gateways 3 and 5 can also be realized by the same device. It is also possible to realize a multi-stage connection configuration using a plurality of gateways 3 and 5.

(Fifth embodiment)
The present embodiment can be implemented as a program that, when installed in a general-purpose information processing apparatus, causes the general-purpose information processing apparatus to realize functions corresponding to the functions of the gateways 3 and 5 of the present embodiment. This program is recorded on a recording medium and installed in a general-purpose information processing apparatus, or installed in a general-purpose information processing apparatus via a communication line, so that the general-purpose information processing apparatus can be connected to the H of the gateways 3 and 5. . 223 bit stream reception processing units 10, 30 and H.264. 223 bit stream division processing units 11, 31, H.264. 223 bit stream packetization processing units 12, 33, 223 packet transmission processing units 13 and 34, H.264. 223 packet reception processing units 20, 40, 223-bit stream extraction processing units 21 and 42, H.264. 223 bit stream combination processing units 22, 43, Functions corresponding to the 223 bit stream transmission processing units 23 and 44, the RTP header addition processing unit 32, and the RTP header analysis processing unit 41 can be realized. The general-purpose information processing apparatus is, for example, a general-purpose CPU.

  According to the present invention, when terminals connected to a circuit switched network transmit / receive bit streams via the packet switched network, the terminal information can be transmitted to each other. The bit stream can be transmitted and received without being aware of the existence of the exchange network, and the service quality is improved.

1 is an overall configuration diagram of an incoming call transfer system according to an embodiment. FIG. The principal part block block diagram of the gateway of a 1st and 2nd Example. The principal part block block diagram of the gateway of a 1st and 2nd Example. H. Explanatory drawing of the effect by the division | segmentation for every MUX-PDU of a 223 bit stream. The principal part block block diagram of the gateway of a 3rd and 4th Example. The principal part block block diagram of the gateway of a 3rd and 4th Example. The whole block diagram of the conventional call transfer system.

Explanation of symbols

1, 7 3G-324M terminal 2, 6 Circuit switching network 3, 5, 300, 500 Gateway 4 Packet switching network 10, 30 223 bit stream reception processing units 11, 31 H.264. 223 bit stream division processing units 12, 33 H.264. 223 bit stream packetization processing units 13 and 34 H.264. 223 packet transmission processing unit 20, 40 H.264. 223 packet reception processing units 21 and 42 H.264. 223 bit stream extraction processing units 22, 43 223 bit stream combination processing units 23, 44 H.264. 223 bit stream transmission processing unit 32 RTP header addition processing unit 41 RTP header analysis processing units 301 and 501 H.245 processing units 302, 502 H.264. 223 demultiplexer

Claims (10)

Packet exchange is performed between terminals connected to the circuit switching network via at least one gateway that transfers a bit stream from the circuit switching network to the packet switching network and at least one gateway that transfers the bit stream from the packet switching network to the circuit switching network. In an incoming call transfer method for sending and receiving a bitstream via a network,
The terminal is a 3GPP standard 3G-324M terminal,
The bit stream is an ITU-T recommendation H.264. 223,
The gateway for transferring a bit stream from the circuit switching network to the packet switching network receives the H.264 received from the circuit switching network. The 223-bit stream is divided into predetermined lengths, UDP (User Datagram Protocol) packets are transferred to the packet switching network,
The gateway for transferring a bit stream from the packet switching network to the circuit switching network is an H.264 packetized from the packet switching network into a UDP packet. A H.223 bit stream is received and extracted from this UDP packet. 223 bit stream is transferred to the circuit switching network.   Instead of dividing into the predetermined length, H. The incoming call transfer method according to claim 1, wherein the incoming call transfer method divides each MUX-PDU (Multiplex-Protocol Data Unit) which is a constituent unit of a 223-bit stream. The divided individual H.P. RTP (Real-time) for each 223-bit stream
3. The incoming call transfer method according to claim 1, wherein a (Transport Protocol) header is added. A gateway for transferring a bit stream from the circuit switching network to the packet switching network, and a gateway for transferring the bit stream from the packet switching network to the circuit switching network;
Each terminal connected to the circuit switched network has means for transmitting and receiving a bit stream to and from the terminal connected to the circuit switched network via the packet switched network through each of the gateways. In the transfer system,
The terminal is a 3GPP standard 3G-324M terminal,
The bit stream is an ITU-T recommendation H.264. 223,
The gateway is
H. received from the circuit switched network. Means for dividing a 223-bit stream into a predetermined length, making a UDP packet, and transferring the packet to the packet switching network;
H.D. converted from the packet switching network into a UDP packet. A H.223 bit stream is received and extracted from this UDP packet. Means for transferring a 223-bit stream to the circuit-switched network.   Instead of dividing the gateway into the predetermined lengths, 5. The call transfer system according to claim 4, further comprising means for dividing each MUX-PDU, which is a constituent unit of a 223-bit stream.   The gateway is connected to the divided individual H.264. 6. The call transfer system according to claim 4, further comprising means for adding an RTP header to each of the 223-bit streams. In a gateway that transfers a bit stream between a circuit switched network and a packet switched network,
An ITU-T recommendation H.264 received from a 3GPP standard 3G-324M terminal connected to the circuit switching network. Means for dividing a 223-bit stream into a predetermined length, making a UDP packet, and transferring the packet to the packet switching network;
H.D. converted from the packet switching network into a UDP packet. A H.223 bit stream is received and extracted from this UDP packet. Means for transferring a 223-bit stream to the circuit switched network.   Instead of dividing into the predetermined length, H. 8. The gateway according to claim 7, further comprising means for dividing each MUX-PDU that is a constituent unit of a 223-bit stream.   The divided individual H.P. 9. The gateway according to claim 7, further comprising means for adding an RTP header to each of the 223-bit streams.   A program that, when installed in a general-purpose information processing apparatus, causes the general-purpose information processing apparatus to realize a function corresponding to the function of the gateway according to any one of claims 7 to 9.

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