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CHAPTER 5: Troubleshooting
10. Can wireless products support printer sharing?
Wireless products perform the same function as LAN products. Therefore,
wireless products can work with NetWare
®
, Windows 2000, or other LAN
operating systems to support printer or file sharing.
11. Would the information be intercepted while transmitting on air?
WLAN features two-fold protection in security. On the hardware side, as with
Direct Sequence Spread Spectrum technology, it has the inherent security
feature of scrambling. On the software side, WLAN series offer the encryption
function (WEP) to enhance security and access control. Users can set it up
depending upon their needs.
12. What is DSSS? What is FHSS? And what are their differences?
Frequency Hopping Spread Spectrum (FHSS) uses a narrowband carrier that
changes frequency in a pattern that is known to both transmitter and receiver.
Properly synchronized, the net effect is to maintain a single logical channel.
To an unintended receiver, FHSS appears to be short-duration impulse noise.
Direct Sequence Spread Spectrum (DSSS) generates a redundant bit pattern
for each bit to be transmitted. This bit pattern is called a chip (or chipping
code). The longer the chip is, the greater the probability that the original
data can be recovered. Even if one or more bits in the chip are damaged
during transmission, statistical techniques embedded in the radio can recover
the original data without the need for retransmission. To an unintended
receiver, DSSS appears as low-power wideband noise and is rejected (ignored)
by most narrowband receivers.
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).