Planet Technology 802.11g Manuel d'utilisateur télécharger pdf (Page 33)

13. What is Spread Spectrum？

Spread Spectrum technology is a wideband radio frequency technique developed by the military

for use in reliable, secure, mission-critical communication systems. It is designed to trade off

bandwidth efficiency for reliability, integrity, and security. In other words, more bandwidth is

consumed than in the case of narrowband transmission, but the trade off produces a signal that

is, in effect, louder and thus easier to detect, provided that the receiver knows the parameters of

the spread-spectrum signal being broadcast. If a receiver is not tuned to the right frequency, a

spread –spectrum signal looks like background noise. There are two main alternatives, Direct

Sequence Spread Spectrum (DSSS) and Frequency Hopping Spread Spectrum (FHSS).

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Planet Technology 802.11g Manuel d'utilisateur Page 33