Study of Channel Characteristics of Power Line Communications Networks

Channel characteristics of Power line is very important because power line is not designed for data transmission and hostile for communications. This paper presents the testing results of channel properties of power line communications networks in China. According to the nature of distribution networks, office blocks and residential buildings are tested respectively. The testing results show that the main reason influencing the reliable communication of highspeed data of power line is the attenuation of the highfrequency signal, which exhibits more obviously in the branch of power line. For the multi-layer building, it is almost impossible to use the frequency range from 2MHz to 20MHz to realize the reliable communication from distribution transformer to each user, and it must be solved with the aid of such means as the repeater etc. Considering the signal’s attenuation, the lower frequency range is more suitable for the high-speed data communication of power line. So the frequency range of 2MHz-10MHz is suitable for the high-speed data access system of power line. For the question of attenuation, it can be solved with the aid of relaying technique.