Abstract: Disclosed is a mobile communication system preventing the transmission of acknowledgements at a burst leading to a decrease in throughput caused by detecting the retransmission and the congestion of packets at the protocol of a transport layer. In a mobile communication system including a mobile terminal and gateway equipment for relaying a packet between a communication partner and the mobile terminal, if the gateway equipment receives the acknowledgement from the mobile terminal, the gateway equipment waits the transmission of the received acknowledgement to the communication partner until the estimated transmission time passes from the time at which the gateway equipment receives the previous acknowledgement from the mobile terminal.

Abstract: After a first base station connects to a first mobile terminal, a first GW (gateway) receives a request for connection between the first mobile terminal and a second GW and identifiers of the second GW and the first mobile terminal and transmits identifiers of the first mobile terminal and the first GW to the second GW. The second GW transmits an MPLS allocation flag to the first GW. The first GW transmits an MPLS allocation signal including an identifier of the first mobile terminal to the second GW via a second NW (network) apparatus. The first base station receives an identifier of the first GW and the MPLS allocation flag from the first GW via a management server and transmits the MPLS allocation signal including the identifier of the first mobile terminal to the first GW via a first NW apparatus.

Abstract: There is provided a communication system in which semi-duplex many-to-many multicasting service can be performed to both a mobile station and a base station by using a unified call control protocol such as SIP on an IP network, and can contain mobile stations and base stations of existing wireless facilities. The communication system in which the semi-duplex many-to-many multicasting service is performed to plural mobile stations 100a, 100b 100c and 110 includes a gateway 104a to convert a first protocol to connect the mobile station 100a, a base station 101a and the gateway 104a, and a second protocol to connect the gateway 104a, a call control server 105 and a press-talk server 106. The gateways 104a, 104b, 104c and 114a perform the protocol conversion for both communication to the mobile station and communication to the base station, so that the semi-duplex many-to-many press-talk can be realized.

Abstract: In a communication system using an IP tunnel for communication between application processing apparatuses (hereinafter, processing apparatuses), an application can be moved to an arbitrary processing apparatus, update of tunnel tables included in the respective processing apparatuses is quickly performed, and a buffer for waiting for packets during the table update is made small. A redundancy managing apparatus manages a correspondence between a virtual IP address (VIP) of an application in a communication system and an IP address (RIP) of an processing apparatus to execute the application. The processing apparatus notifies the VIP of the communication partner application of the application to the redundancy managing apparatus.

Abstract: Disclosed is a mobile communication system preventing the transmission of acknowledgements at a burst leading to a decrease in throughput caused by detecting the retransmission and the congestion of packets at the protocol of a transport layer. In a mobile communication system including a mobile terminal and gateway equipment for relaying a packet between a communication partner and the mobile terminal, if the gateway equipment receives the acknowledgement from the mobile terminal, the gateway equipment waits the transmission of the received acknowledgement to the communication partner until the estimated transmission time passes from the time at which the gateway equipment receives the previous acknowledgement from the mobile terminal.

Abstract: When half-duplex many-to-many communication is performed among a plurality of mobile stations having different codecs in a single group, transcoding is performed with a small number of codec circuits. A transcoder manages an SSRC of a received RTP packet, detaches voice information from a jitter buffer, which is identical to a latest SSRC, and inputs the detached voice information to a codec circuit. As the latest SSRC is switched, a voice sending station subject to transcode is switched, and mobile stations using the same codec share the codec circuit. Therefore, in a half-duplex many-to-many communication (group communication) system, called a professional mobile radio system, push-talk, or press-talk, it is not necessary to switch the transcoder until a radio station which takes a talk burst is changed during a single call (call session).

Abstract: In a communication system using an IP tunnel for communication between application processing apparatuses (hereinafter, processing apparatuses), an application can be moved to an arbitrary processing apparatus, update of tunnel tables included in the respective processing apparatuses is quickly performed, and a buffer for waiting for packets during the table update is made small. A redundancy managing apparatus manages a correspondence between a virtual IP address (VIP) of an application in a communication system and an IP address (RIP) of an processing apparatus to execute the application. The processing apparatus notifies the VIP of the communication partner application of the application to the redundancy managing apparatus.

Abstract: When half-duplex many-to-many communication is performed among a plurality of mobile stations having different codecs in a single group, transcoding is performed with a small number of codec circuits. A transcoder manages an SSRC of a received RTP packet, detaches voice information from a jitter buffer, which is identical to a latest SSRC, and inputs the detached voice information to a codec circuit. As the latest SSRC is switched, a voice sending station subject to transcode is switched, and mobile stations using the same codec share the codec circuit. Therefore, in a half-duplex many-to-many communication (group communication) system, called a professional mobile radio system, push-talk, or press-talk, it is not necessary to switch the transcoder until a radio station which takes a talk burst is changed during a single call (call session).

Abstract: There is provided a communication system in which semi-duplex many-to-many multicasting service can be performed to both a mobile station and a base station by using a unified call control protocol such as SIP on an IP network, and can contain mobile stations and base stations of existing wireless facilities. The communication system in which the semi-duplex many-to-many multicasting service is performed to plural mobile stations 100a, 100b 100c and 110 includes a gateway 104a to convert a first protocol to connect the mobile station 100a, a base station 101a and the gateway 104a, and a second protocol to connect the gateway 104a, a call control server 105 and a press-talk server 106. The gateways 104a, 104b, 104c and 114a perform the protocol conversion for both communication to the mobile station and communication to the base station, so that the semi-duplex many-to-many press-talk can be realized.

Abstract: A public mobile terminal can use both of a public mobile communication service and an extension service while protecting an SIP message by an IP sec. An indoor call control apparatus that receives an INVITE message from the public mobile terminal has a destination determination table that determines whether the called terminal is an indoor terminal, or not. When the terminal is the indoor terminal, a Route header is deleted from the INVITE message, and the message is transmitted to the called terminal. When the called terminal is not the indoor terminal, the INVITE message is transmitted to an S-CSCF of a calling terminal on the basis of the contents of the Route header.