Credit: ccarlstead CC-BY 2.0. Playing cards developed their four-suit design in the 1480s in France. By the late 1800s, factories mass-produced standard English playing cards that featured diamonds, hearts, clubs and spades, a design that prevails as of September 2014. Older cards were based on Latin suits of cups, swords, coins and rods.
Definition - What does Spread Spectrum mean? Spread spectrum is a technique used for transmitting radio or telecommunications signals. The term refers to the practice of spreading the transmitted signal to occupy the frequency spectrum available for transmission.
A range of frequencies used for transmission or reception of radio waves (e.g. 10 7 GHz to 12 75 GHz)... The term frequency spectrum is also used more generally to refer to a continuous range of frequencies.