Abstract: An optical-switch driver circuit includes a pulse signal source and a voltage-applying circuit. The pulse signal source generates pulse waves that rise from a first voltage to a second voltage. The voltage-applying circuit, for one of the pulse waves, outputs a voltage higher than the third voltage, then outputs a voltage lower than the third voltage, and further outputs the third voltage.

Abstract: An optical-switch driver circuit includes a pulse signal source and a voltage-applying circuit. The pulse signal source generates pulse waves that rise from a first voltage to a second voltage. The voltage-applying circuit, for one of the pulse waves, outputs a voltage higher than the third voltage, then outputs a voltage lower than the third voltage, and further outputs the third voltage.

Abstract: A wireless communication terminal including a wireless communication unit for receiving and transmitting voice signals between terminals connected through a voice channel and a data channel, a signal input/output unit for inputting and outputting voice signals for voice communication and a mixing unit, interposed between the wireless communication unit and signal input/output unit, for performing mixing operations to create a first mixed signal to be output to said signal input/output unit and second mixed signals each to be transmitted to the corresponding terminal. The wireless communication terminal is preferably used for wireless voice communication performed by three or more terminals without being interposed by a center apparatus (such as a server) or a repeater. Further, signal-receiving/transmitting is set for each wireless communication terminal whereupon convenience can be improved.

Abstract: A system for receiving inquiry by speech includes a plurality of receiving board apparatus capable of receiving an inquiry by speech from an inquirer, a VoIP gateway apparatus connected via the LAN to a plurality of receiving apparatuses for transmitting/receiving via the LAN to/from the receiving board apparatus a speech packet containing speech data relating to communication between the recipient of the receiving board apparatus which has answered to an inquiry and inquirer, and a speech multiplexing HUB apparatus for receiving speech data input to each receiving board apparatus, time-division multiplexing them, and distributing them in parallel to each receiving board apparatus.

Abstract: A wireless communication terminal including a wireless communication unit for receiving and transmitting voice signals between terminals connected through a voice channel and a data channel, a signal input/output unit for inputting and outputting voice signals for voice communication and a mixing unit, interposed between the wireless communication unit and signal input/output unit, for performing mixing operations to create a first mixed signal to be output to said signal input/output unit and second mixed signals each to be transmitted to the corresponding terminal. The wireless communication terminal is preferably used for wireless voice communication performed by three or more terminals without being interposed by a center apparatus (such as a server) or a repeater. Further, signal-receiving/transmitting is set for each wireless communication terminal whereupon convenience can be improved.