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machine's MAC address and then adds a relatively large 16-octet initialization vector to produce
the key that will encrypt the data. This procedure ensures that each station uses different key
streams to encrypt the data.
ü
Can Wireless products support printer sharing?
Wireless products perform the same function as LAN products. Therefore, Wireless products
can work with Netware, Windows NT/2000/XP, or other LAN operating systems to support
printer or file sharing.
ü
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.
ü
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, 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.
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).
