Hitachi, Ltd.

Yuichiro Katsu

Masao Hayama

Yoshiyuki Machida

Shirou Mazawa

Fumihiko Shimazaki

Koji Watanabe

Masahiro Takatori

Shiro Mazawa

Masashi Yano

Yosuke Takahashi

Hiroto Nakagawa

Norihisa Matsumoto

Hitomi Nakamura

Tsutomu Uchida

Dan Xu

To realize a handover in which a gateway connecting to the access networks using different protocols is an anchor. In a communication system, the gateway holds a service identifier management table for converting a service identifier of different kind with the protocol into a PDN identifier, and at the time of handover, specifies a session to be held with the user identifier and the PDN identifier, selects the same PDN connected to the movement source, and reassigns the same IP address that has been already assigned at the movement source.

Communication system and method, and gateway

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

In a radio communication system wherein radio frequencies for communicating with a radio terminal are different in radio base stations, a table in which positional information, information on the frequency used for transmission/reception to/from the terminal, and a decision condition in a handoff operation are stored as to each base station is prepared in a base station controller beforehand. When the positional information is received from the radio terminal, the base station controller selects the base station being a handoff candidate, on the basis of the positional information of the radio terminal, the positional information of each base station and the decision condition of the handoff operation with reference to the table, and it transmits a handoff request message which contains the information on the frequency of the base station being the handoff candidate, to the radio terminal through the base station communicating with the radio terminal.

Radio access terminal, base station controller, and handoff control method in radio communication system

A radio communication system arranged to deliver multimedia information into a plurality of mobile stations is arranged to deliver the multimedia information according to the wave circumstances of each mobile station, layer the information components composing the multimedia information, create the frame containing the layered information components and the transmission priorities of the components, connect the frames on a multimedia information unit, and then transmit the connected frames to a base station.

Base station apparatus, mobile station, and contents provider

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Yokohama, Japan

Yuichiro Katsu