Seeing an opportunity to enter the growing US telecom market afforded by new, optical fiber technology (The US Communications Act of 1934 prohibited ownership of radio facilities by foreign owned companies), Cable & Wireless acquired 9xDS3s from MCI along the Amtrak right of way and began selling transmission services. Among its early customers was a company named TDX Systems. In 1986, the US long distance industry was deregulated, and many new companies launched into the equal access market. TDX Systems, based in Falls Church, Virginia, was one of these, with a footprint between Washington, DC and New York. TDX carried data (analog modem up to digital DS3), and built its own telephone switches at its engineering facility in Chantilly, VA. TDX voice switches, called "SSTs" (satellite switching terminal) were centrally controlled nationwide by Perkin-Elmer mainframes in Falls Church, and were some of the first long-distance switches to utilize least-cost routing, follow-on account codes and PINs. For a short time, TDX touted a position of being one of the primary providers of phone and data service for the World Trade Center.