User's Manual

Wireless PCMCIA Card
22
ü 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).