System Control Design via AC Line for Security System

In this paper, we present the system control design via AC line for the security system. The system comprises houses and control node such as center control, node control and home control which are connected as the two levels network called master-slave model. Our system can support the data rate up to 9,600 bits per second with the maximum distance at 1,200 meters. The transmission data are encrypted using DES algorithm. Moreover, the system can connect to the Internet by using Web service protocol and only one IP address is needed for our system. The measurement of electricity can be done automatically. We design the protocol for controlling all the electric equipments via AC line with FSK modulation technique, which can support the data rate up to 250 bits per second with the distance at 300 meters. We evaluate the performance of our system by means of experiment. The results showed that we can achieve 99.99 and 99.92 percents for the transmission without error on the network and AC line, respectively. We also examine the signal attenuation depends on the number of load, load type and position of load between transmitter and receiver