Cisco WAP2000 Administration Manual page 75

Troubleshooting
Cisco WAP2000 Wireless-G Access Point with Power Over Ethernet Administration Guide
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).
What is DSSS? What is FHSS? And what are their differences?
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.
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.
Would the information be intercepted while transmitting on air?
WLAN features two-fold protection in security. On the hardware side, as with
DSSS technology, it has the inherent security feature of scrambling. On the
software side, the WLAN series offers a variety of wireless security methods to
enhance security and access control. Users can set it up depending upon their
needs.
Can Cisco wireless products support file and printer sharing?
Cisco wireless products perform the same function as LAN products. Therefore,
Cisco wireless products can work with NetWare, Windows NT/2000, or other LAN
operating systems to support printer or file sharing.
What is WEP?
WEP is Wired Equivalent Privacy, a data privacy mechanism based on a 40-bit
shared-key algorithm, as described in the IEEE 802. 1 1 standard.
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