Abstract: Disclosed is a wireless surveillance system comprising a probe (200) and a control center, obviating the need for battery replacement, and completely powered by solar energy. During disarmed periods, the probe (200) ceases to probe the external thereof, and ceases to transmit data to the control center. A receiver (201) of the probe (200) works in consecutive turned-on/turned-off modes. A turned-on time of the receiver (201) is greater than or equal to the power-up latency time of the probe (200). The receiver (201) is provided without frequency changer, intermediate frequency band-pass filter, and low frequency band-pass filter. The probe (200) comprises a human-machine interface (209) for use in displaying light intensity. Also disclosed is a method for controlling the operation of a wireless device. The receiver (201) is controlled by a trigger signal to work in the consecutive turned-on/turned-off modes, where the turned-on time is greater than or equal to the power-up latency time of the receiver (201).

Abstract: A baby monitor which eliminates potential harmful microwave effect of wireless signal generated by current wireless baby monitors. The baby monitor has a nursery unit, a parent unit, and optionally a gateway. The nursery unit consists of video or audio acquisition, amplifier, microcontroller, microcontroller-controlled band-pass filter, microcontroller-controlled carrier generator and modulator, power line coupling circuitry. It transmits signal to the parent unit or the gateway through power line. Parent unit includes power line coupling circuit, micro-controller, microcontroller-controlled band pass filter, super-heterodyne amplifier, video/audio modulator and video/audio player. Alternatively, the power coupling circuit, microcontroller, microcontroller-controlled band-pass filter and super-heterodyne amplifier in the parent unit can be separated and form a gateway device which then communicates with the parent unit wirelessly.