Sensor Based versus Server Based Image Detection Sensor using the 433 Mhz Radio Link

The 433 MHz radio link is one of the free license industrial, scientific and medical (ISM) bands that is freely available for many applications. Since frequency license is a hurdle when applying wireless sensor, the use of free license bands is popular. However, the 433 MHz radio link is limited in capacity. Moreover, bitrates decrease in crowded environment. Wireless sensor may face bandwidth constraint. Wireless sensor with numeric data collection may have no difficulties to transmit its data, but image sensor may take longer to send its image. This paper examines the advantages and drawbacks of wireless image or video sensor for detecting human or animal in which its data is sent to server by using the 433 MHz radio link. Object detection is either performed in sensor or in server. Experiments show that local detection is preferred as the only drawback is power consumption to process detection within sensor. The binary result of local detection can be sent only by using small packet of the 433 MHz radio frame. If necessary, one sample image containing the detected object can be sent to server by shorter time compared to when wireless sensor sends all images to server.