Hitachi, Ltd.

Hitachi Communication Technologies, Ltd.

Michio Iguchi

Shiro Mazawa

Yosuke Takahashi

Hisanori Matsumoto

Arata Nakagoshi

Tsutomu Sano

Masao Hayama

Takanori Moritomo

Changho Han

Ichiro Kohashi

There is disclosed a method of detecting failures or anomalies of a large number of sensor terminals without using manpower or expensive equipment in the seismic exploration business. The method includes preparing a plurality of sensor terminals having sensors that detect vibrations from outside, the plurality of sensor terminals receiving the vibrations and outputting vibration reception signals, and comparing a first vibration reception signal output by a first sensor terminal with a second vibration reception signal output by a second sensor terminal, thereby detecting if one of the first sensor and the second sensor is failed or anomalous.

Method of detecting failure or anomaly of sensor terminal

When a mobile station registered at a closed-type femtocell base station is in a connection state in a cell area covered by the femtocell base station, the transfer power of the femtocell base station for a cell identification signal is adjusted according to one scale estimating the receiving quality of the cell identification signal at the mobile station. When no mobile station is located in the cell area covered by the femtocell base station, the cell identification signal is sent with the minimum transmission power necessary for a mobile station to make a call in the cell area to reduce the power consumption of the femtocell base station and also to reduce interference with other macrocell base stations and other femtocell base stations.

Radio communication system, radio communication method, and base station

A wireless base station for transmitting and receiving a wireless signal with at least one wireless terminal existing in an area, having a transmitter for transmitting the wireless signal, and a receiver for receiving the wireless signal; a timing management unit for managing the information on start timing of the transmitter and receiver, as well as noticing the information on start timing of the transmitter and receiver to the at least one wireless terminal; and a control unit for performing the switching control of start and stop of the transmitter and receiver.

Wireless base station, wireless terminal and wireless communication system

The present invention can be achieved by a base station in which a terminal is accommodated and the terminal is communicated with another terminal, and which includes: a data rate operation/management unit which operates and stores a time-averaged data rate Rave of the terminal; a threshold value operation/management unit which obtains a current communication data rate R of the terminal to operate and store R/Rave; and a delay management unit which controls to reduce delay on the basis of the R/Rave.

Base station

In a case where a cellular phone exists outside a WOS system service area, the cellular phone receives a not-connectable signal and an audio message from a mobile switching controller. The cellular phone conducts disconnection processing with the not-connectable signal as a turning point. Moreover, the cellular phone stores an extension number and converts a dedicated special number into an external number for retransmission, thus establishing connection to a PBX. After the reception of a connection-accepted signal and an automatic exchange answer message from the PBX, the cellular phone automatically transmits the stored extension number.

Cellular phone and mobile switching controller

In a case where a switching source wireless communication system is a wireless communication system in which a transmission timing of a packet or data rate can be controlled in a wireless base station, the switching source wireless communication system, which notifies information on a timing when a wireless terminal communicates the switching destination wireless communication system with respect to the switching source wireless communication system in advance, starts time-division communication between switching destination and switching source wireless communication systems, and receives the timing information, controls a transmission timing or a data rate in accordance with the timing information.

Growing community of inventors

Yokohama, Japan

Michio Iguchi