In Access broadband over power line (BPL) systems, a BPL repeater is a device used to boost the distance the signal can travel. broadband over power line (BPL). A typical BPL signal travels only for 1,000 to 3,000 feet down line, and a BPL repeater can be used to increase the distance the signal can travel. There is often a decrease in system performance when a repeater is used. Also called a BPL regenerator.