DSS stands for “Digital Spread Spectrum”, a highly robust radio system that was initially confined to exotic defence communications. Spread spectrum was primarily used by the military in the 1940s and 1950s for communication systems to send and receive secure data. It has only been since about 1985 that it’s been available for use by the general public. Now it has come to radio control for model aircraft and it is revolutionising the scene.
This Silvertone Flamingo UAV has a 4-metre wingspan, can fly at 95 knots and is fitted with 2.4GHz DSS system.
The idea for spread spectrum communications originally came from the film actress Hedy Lamarr who conceived and patented a frequency hopping system using something akin to piano rolls. The technology originally could not support this system and the idea lay dormant for many years but was eventually picked up and developed into the modern spread spectrum system.
You can read more about Hedy Lamarr’s patent and a lot of other interesting information at http://www.inventions.org/culture/female/lamarr.html
As near as I can ascertain, the pioneer of spread spectrum R/C systems was Dave Jones of AUAV, based in Florida, USA. In 2000, Dave began experimenting with Digital Spread Spectrum R/C systems for use in his UAVs (Unmanned Aerial Vehicles). He chose Digital Spread Spectrum (DSS) for its tight security and outstanding ability to reject intentional or unintentional radio frequency interference.
Dave Jones was looking to conduct a flight of a 3-metre UAV to an altitude of 30,000 feet. As you can imagine, one of the biggest concerns was how to ensure rock solid, reliable control of the aircraft. They had planned to conduct most of the flight under autonomous control but still wanted to have the ability to take over manually or make changes in the flight profile should the need arise.