Planet WL-U356, Руководство пользователя

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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).