Autovon

The Automatic Voice Network (AUTOVON, military designation 490-L) was a world-wide American military telephone system. The system was built starting in 1963, based on the Army's existing Switch Communications Automated Network (SCAN) system. In June 1966 the Air Defense Command voice network was cut over to the new service. In 1969, AUTOVON switching centers opened in the United Kingdom, and later in other European countries, Asia, the Middle East, and Panama. It was a major part of the Defense Communications System (DCS), providing non-secure switched voice services. The system was replaced in the early 1990s by the Defense Switched Network.

AUTOVON used a combination of its own constructed circuits and other lines operated by AT&T Corporation and smaller independent telephone companies, connected by high-speed switching centers produced by Automatic Electric Company to exchanges located far from other civilian or military targets. In the US the cables were predominantly L-carrier coaxial multiplex built by AT&T, who also used them to carry about one third of all civilian long-distance calls, as their capacity was much higher than the military needed. Although unused, some of the cables remain today and the routes are visible on satellite photos. The system's traffic was transported over many media other than underground cable, including microwave links, open wire and, near the end of the system's life, fiber optic. Contrary to stories of underground concrete cable ducts, most of the cable was directly buried without added concrete, relying instead on the natural protection of soil.

Most of the cable repeater huts have been sold to private interests, to round out existing parcels, or as possible build-to-suit tower sites, etc. AT&T has been filling the small underground portion before sale, unless they sell to a major company. The junctions for AUTOVON are also being sold into private ownership, with a few exceptions. Most are stripped of all the equipment, although the AUTOVON junction in Mounds, Oklahoma was sold with all the old equipment in place.

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