American Radio Relay League

Definition
The American Radio Relay League (ARRL) is the U.S. organization of licensed amateur radio operators that use short-wave radios to communicate with other such operators.

Overview
In times of emergency such as floods, the aftermath of storms and other events that disrupt conventional communication, "hams," as they call themselves. can offer a vital communication link to those in need and to those responding to the emergency.

Broadband over power line (BPL) can potentially interfere with short-wave radio communications and mitigating that interference was the goal of an FCC 2004 report and order.