Hitachi, Ltd.

Toshiichiro Sasaki

Minoru Koizumi

Tomoichi Ebata

Yoshiaki Adachi

Chiho Kitahara

Takeshi Ishizaki

Koji Suzuki

Junji Fukuzawa

A technique for performing message communications while assigning a space and respective time periods or time points at present, in past and in future is disclosed. A space-time object intercepts a message. Alternatively, this object per se executes the processing for immediately transmitting a message to a target object under management with relevancy thereto, for retaining the message by a future time point assigned, or for preparing and sending a message for searching logs in the past, thereby to realize the space-time communications.

Space-time communication system

In order to allow efficient use of bandwidth in communication paths in a surveillance system, the surveillance system has an operation unit which assigns fixed bandwidths to each of the communications taking place between camera nodes, which transfer image data at a uniform rate, and monitor nodes. A fixed bandwidth is assigned to, all communications taking place between the operation unit and sensor nodes, which generate alarm information at a non-uniform rate. If there is an increase in network traffic, bandwidth allocations, for communication between the camera nodes and the monitor nodes are reassigned so that bandwidth for these communications is reduced. The camera nodes use the bandwidth assigned to the camera nodes to transfer image data. The sensor nodes transfer alarm information using any bandwidth.

Method of controlling quality of communication among a plurality of clients over a network

Surveillance system and network system

Growing community of inventors

Iwaki, Japan

Toshiichiro Sasaki