Hitachi, Ltd.

Hitachi-Kokusai Electric Inc.

Norihisa Matsumoto

Masashi Yano

Naruhito Nakahara

Nodoka Mimura

Koji Watanabe

Susumu Matsui

Tetsuhiko Hirata

Hitomi Nakamura

Shoji Fukuzawa

Toshiro Suzuki

Masahiro Takatori

Yosuke Takahashi

Masato Hayashi

Seishi Hanaoka

Mika Mizutani

Takehiro Morishige

Minoru Ogushi

Yuichiro Katsu

Hidetoshi Nishiyama

Atsushi Teshima

Makoto Watanabe

Kazuhisa Tanaka

A communication system which includes plural radio systems, and which connects to a terminal apparatus corresponding to the plural radio systems, comprising: access points for the each radio system; gateways; an authentication apparatus; and a home agent. The authentication apparatus being shared by the plural radio systems: assigns an IP address to the terminal apparatus in a radio system which is initially connected among the plural radio systems according to an IP address assignment request from the terminal; judges whether an IP address assignment request for a radio system to be subsequently connected is from the same terminal apparatus by using an unique identifier of the terminal; and assigns the IP address assigned in the initially connected radio system to the terminal apparatus in the radio system to be subsequently connected in a case where the assignment request is determined to be from the same terminal apparatus.

Communication system using multi-radio mode, monitor node apparatus, control node apparatus and base station apparatus

A communication system comprising a home server, an access gateway, and a policy server, wherein the policy server transmits, to the first access gateway, a link creation request for associating a communication path of the first terminal and a communication path of the second terminal; and the access gateway sets a fifth communication path which connects the first communication path and the third communication path upon receiving the link creation request, records information on the set fifth communication path in the communication path management information, and transmits the data from the first terminal via the first communication path to the second terminal via the fifth communication path and the third communication path based on the communication path management information.

Communication system and access gateway apparatus

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 stationsandincludes a gatewayto convert a first protocol to connect the mobile station, a base stationand the gateway, and a second protocol to connect the gateway, a call control serverand a press-talk server. The gatewaysandperform 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.

Communication system and gateway

A wireless system includes plural different access networks and terminals () having interfaces corresponding to the plural different access networks (). Each of the access networks includes an access gateway (AGW) performing flow control. Upon receiving a packet transmission stop signal, the AGW determines whether a predetermined message transmitting chance is given. The AGW includes a control unit that transmits a message that requests a handover to another access network to a terminal when the message transmitting chance is given. The terminal includes a unit that performs a handover to another access network, upon receiving the message.

Access gateway, terminal and method of controlling flow in wireless system

Disclosed herewith is a communication system, which can solve the following conventional problem that if packets exchanged between a terminal and an HA are encapsulated with use of the mobile IPv6 protocol, the PDSN cannot identify any IP flows in the mobile IPv6 tunnel. Consequently, there is no QoS usable appropriately to the services in the EV-D0 RAN. To solve such a problem, the PCRF notifies the HA of the filter information used to specify each IP flow and the flow label assigned to each IP flow. The HA then sets the flow label in the outer IPv6 header of the packet matching with the filter information and transfers the packet to the object unit. The PDSN then refers to the flow label set in the outer IPv6 header to identify the object IP flow in the mobile IPv6 tunnel. Consequently, a proper QoS can be usable for the services respectively in the EV-D0 RAN.

Communication system, server, control apparatus and communication apparatus

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. The redundancy managing apparatus notifies the VIP of the communication partner application of the moved application and the RIP of the processing apparatus to execute the communication partner application to the processing apparatus of the movement destination (failover destination) of the application.

Redundant failover system, redundancy managing apparatus and application processing apparatus

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).

Press-talk server, transcoder, and communication system

When congestion occurs in a RAN in a cell phone VoIP service, calls using the congested device are detected to permit generation of a restriction in call by call units. The congested device notifies call connection data passing through it to a PDSN, the PDSN finds the IP address of the terminal using the target connection, and notifies a CSCF as a restriction target terminal. The CSCF, in call connection processing, determines whether the calling/called sending/receiving user is the restriction target, and if so, determines whether or not the call should be connected with priority from subscriber data.

Communication system and call control server

Disclosed is a network system that can distribute connection requests from PPPoE client terminals to specific PPPoE servers under the initiative of the PPPoE servers. In the system that realizes connection between at least one client terminal and plural servers at least by a connection start signal from the client terminal, a connection provision signal from the servers, corresponding to the connection start signal, and a connection request signal from the client terminal, corresponding to the connection provision signal; the servers have an identification information setting means, upon receiving a connection start signal from the client terminal, for setting server identification information for identifying a specific server to receive a connection request signal corresponding to the connection start signal in the connection provision signal.

PPPoE network system that can distribute connection requests from PPPoE client terminals to specific PPPoE servers

In a mobile IP network system containing a plurality of radio access networksfor connecting with mobile stationsvia radio links and an IP networkconnected with a plurality of packet nodes for transferring IP packets, each of the radio access networks has at least one base station controllerand at least one radio base stationconnected to the base station controller. Each of the base station controllersin the radio access network is connected to the plurality of packet nodes to each other via a networkand selects one of the plurality of packet nodes in accordance with a state of each mobile station to establish a logical connection to be used in IP packet communication of the mobile station.

Mobile IP network system and connection switching method

A mobile communication system that can obtain mobile station location information repeatedly at short intervals, without depending on whether base stations are synchronous or asynchronous, with lower loads and suppressed use of radio resources. For obtaining location information, a mobile station receives a paging channel periodically sent from a base station (Step ), obtains the contents and the reception timing of this paging channel. Further, if it is necessary to obtain the transmission timing of the paging channel, that transmission timing is obtained (Steps ). The propagation delay of the paging channel or propagation delay differences between a plurality of periodic paging channels are calculated from the transmission timing and the reception timing of the paging channel (Step ). The mobile station location information is calculated from the propagation delay or propagation delay difference, and outputted (Steps ).

Mobile communication system, mobile station, and base station that calculates distance from mobile station

A public key cryptosystem is used for the authentication of a personal station (PS) which subscribes for a plurality of radio communication exchange systems. A public key of PS is registered into a public key DB of a public key management device. A private key is registered into PS. When PS moves into a service area of a certain radio communication exchange system, an exchange in that radio communication exchange system requests the public key management device for a public key of PS and makes a check for authentication of PS based on the public key cryptosystem by use of the received public key. Thereafter, when PS moves into a service area of another radio communication exchange system, an exchange in the other radio communication exchange system similarly requests the public key management device for a public key of PS and receives the same public key. The exchange in the other radio communication exchange system makes a check for authentication of PS based on the public key cryptosystem by use of the received public key. In the case where the authentication between each radio communication exchange system and PS results in success, each radio communication exchange system can determine a peculiar authentication key to inform PS of the peculiar authentication key so that the authentication of PS from that time onward is performed using the peculiar authentication key.

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Fuchu, Japan

Norihisa Matsumoto