Military Use
Spread-spectrum signals are highly resistant to deliberate jamming, unless the adversary has knowledge of the spreading characteristics. Military radios use cryptographic techniques to generate the channel sequence under the control of a secret Transmission Security Key (TRANSEC) that the sender and receiver share in advance.
By itself, frequency hopping provides only limited protection against eavesdropping and jamming. There is a simple algorithm that effectively discovers the sequence of frequencies. To get around this weakness most modern military frequency hopping radios employ separate encryption devices such as the KY-57. U.S. military radios that use frequency hopping include the JTIDS/MIDS family, HAVE QUICK and SINCGARS.
Read more about this topic: Frequency-hopping Spread Spectrum
Famous quotes containing the word military:
“There are many examples of women that have excelled in learning, and even in war, but this is no reason we should bring ‘em all up to Latin and Greek or else military discipline, instead of needle-work and housewifry.”
—Bernard Mandeville (1670–1733)
“War both needs and generates certain virtues; not the highest, but what may be called the preliminary virtues, as valour, veracity, the spirit of obedience, the habit of discipline. Any of these, and of others like them, when possessed by a nation, and no matter how generated, will give them a military advantage, and make them more likely to stay in the race of nations.”
—Walter Bagehot (1826–1877)