Hitachi, Ltd.

Shuichi Miyazaki

Yukihide Inagaki

Hideo Aoe

Koji Hirayama

Haruko Takano

Kiyohiko Yoshida

Shuuichi Kozawa

The original content and the converted content obtained by converting the original content are encrypted by the same content key. A license containing data of use conditions such as the content key and a use period is recorded in an area of a storage medium limited for access. When the converted content is used with an external storage medium, a copy of an original license is created, a use period of the copy is changed to a use period of the converted content designated by a user, and the license is output as a converted content license to the external storage device. The use period of the original content is rewritten to prevent its overlapping with a use period defined by the converted license.

Method and system for preventing simultaneous use of contents in different formats derived from the same content at a plurality of places

In a mobile communication system in which a plurality of base stations are connected to a communication network via a packet transfer node and a transmission rate of a forward link radio channel between a base station and a mobile station dynamically changes, each of the base stations designates a packet transmission rate in accordance with the status of a radio channel of each of mobile stations under control for the packet transmission node, and the packet control node transfers packets destined for each of mobile stations to the base station at the designated transfer rate.

Wireless base station and packet transfer apparatus for dynamically controlling data transmission rate

Growing community of inventors

Yokohama, Japan

Shuichi Miyazaki