Broadband Over Power Lines (BPL) and Its Impact on Spectrum Allocation

For many years the electric utility companies have employed power lines to transmit signals in the tens of kHz range for the control of switches and relays on electric power transmission systems. The electric utility companies and internet providers have become interested in employing existing power lines for providing residential and commercial internet access, using frequencies from 1.6 to 30 MHz to attain data rates of 1 or more Mbitss. Initially intended to provide high-speed internet service to consumers in rural areas, Broadband Over Power Lines BPL is of great interest to service providers as power lines reach virtually every home and community in the country. A major concern with BPL is that the data signals impressed upon power transmission lines can emit disruptive electromagnetic interference EMI to communications and high frequency HF radar receivers residing in the 2-30 MHz band. The NRL Radar Division and the Space and Naval Warfare Systems Center SPAWAR Charleston were tasked by the Naval Sea Systems Command to determine what changes in the ambient background noise levels might result from a BPL installation.