How can we avoid interference from a system that will traverse so many locations? The “spread spectrum” and “multiple carrier” techniques used in proposed BPL systems employ modulation that spectrally resembles noise and can employ system architectures capable of minimizing radiated interference. The multiple carriers can be controlled in amplitude, turned on and off, or “notched” to remove energy radiating at specific frequencies. Typical Access BPL frequencies start above AM radio (1.7 MHz) and end just below FM radio (up to 80 MHz). Usually the entire available range is not used—the upper frequency is typically less than 50 MHz. There are many licensed, incumbent services that must be protected in this frequency range, including:



Amateur Radio – 1.8 – 54 MHz

Short-wave radio – 5.9 – 26.1 MHz

CB Radio – 26.96- 27.41 MHz

TV Channels 2-6

Public Safety bands

Federal Government bands

Aeronautical Stations

Coast Guard Stations

Radio Astronomy Stations