06671520 is referenced by 38 patents.
A remotely operated wireless video/audio hand-held monitoring system comprises a central station having a display and a speaker, and at least one remote terminal having a camera and a microphone. The central station is adapted to send out control command data containing a remote terminal identifier, a communication frequency channel number and any one of a test command, a power on command and a power off command, to receive response data corresponding to the control command data and to reproduce video and audio signals transmitted at a frequency corresponding to the communication frequency channel number, respectively, through the display and speaker in response to the received response data. The remote terminal is adapted to receive the control command data from the central station, to send out the response data corresponding to the received control command data to the central station and to, in a power on mode based on the power on command, drive the camera, the microphone and a video/audio signal transmitter and transmit a video signal from the camera and an audio signal from the microphone to the central station at the frequency corresponding to the communication frequency channel number. Therefore, one portable central station can selectively control one or more remote terminals to monitor images and voices at remote locations.