I.A.G.O.: Command Control Link Using Coded Waveguide

For vehicular communications in automated transportation systems, a very important problem is to maintain high‐quality broadband communications at all locations. Furthermore, to achieve the automated navigation of vehicles, two pieces of information are of great necessity: the knowledge of the real speed of the vehicle and its absolute position along the track. Using a slotted specialized microwave waveguide, a new concept has been developed in France that allows the simultaneous transmission of several TV voice channels and high‐capacity numerical transmissions. It also enables a high‐precision speed measurement without mechanical contact with the ground. Lastly, using different orientations of the slots, a pseudo‐random sequence is read while the vehicle moves along the track, so it is possible to conclude continuously on its absolute position. Working in the 2.4–2.5 GHz industrial, scientific and medical (ISM) band with low radiated power $\left(<\mathrm{dBm}\right)\text{,}$ the system exhibits a 100 MHz bandwidth with limited administrative problems. Its mechanical dimensions enable a rugged construction of the waveguide. Finally, a fairly low linear automation is obtained at this frequency (13–15 dB/km), so that a minimum number of repeaters is required.