Kabushiki Kaisha Toshiba

Kenichi Kitazawa

Motohisa Araki

According to one embodiment, a communication system includes a first terminal to be connected to a first communication network, assigned a terminal ID and driven by power supplied from a battery, a server apparatus to be connected to a second communication network differing from the first network, to periodically confirm presences of the first terminal and a second terminal to be connected to the second communication network, and to communication-connect between the first and the second terminals in the case of presences thereof, and a controller which makes the server apparatus monitor that the first terminal is present on the first communication network by a second period longer than a first period monitoring that the second terminal is present on the second communication network.

Communication system and server apparatus and terminal apparatus

A main equipment is used in a network telephone system including telephone terminals and the main equipment. The telephone terminals are connected to a communication network to transmit voice packets. The main equipment connects the telephone terminals to one another through the communication network to cause the telephone terminals to communicate with each other. The main equipment includes a communication unit and a detection unit. The communication unit transmits connection confirmation signals to the telephone terminals at different timings, respectively. The connection confirmation signals are defined by a communication protocol on the communication network. The connection confirmation signals are used to confirm connection between the telephone terminals and the main equipment. The detection unit detects presence of one telephone terminal when the one telephone terminal sends back a response signal in response to the transmission of the connection confirmation signals.

Growing community of inventors

Hino, Japan

Kenichi Kitazawa