The Global ALE High Frequency Network (HFN) -- an international Amateur Radio Service organization of ham operators dedicated to emergency/relief radio communications -- has become the first network to operate continuously for more than 500 days on all international Amateur Radio shortwave bands simultaneously. According to HFN International ALE Coordinator Bonnie Crystal, KQ6XA, the main purpose of the Network is to provide efficient emergency and disaster relief communications to remote areas of the world. "Beginning with a core group of six North American radio operators in June 2007, HFN rapidly expanded to cover large areas of the planet with 24/7 digital communications," she said."HFN was designed to be an open framework for global Amateur Radio emergency services to interoperate on HF using the Automatic Link Establishment (ALE) system." Relying on ionospheric radio communications, interconnected HFN base stations scan the radio bands every 10 seconds, from 3.5 MHz-28.0 MHz. Through this Net, Crystal said, ham operators stay connected with each other at all hours of the day or night in any mode of operation, and can send Internet e-mail or cell phone mobile text messages from the field."
Source: ARRL website