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An infrastructure network is a group of computers or other devices, each
I
NFRASTRUCTURE
with a wireless adapter, connected as an 802.11 wireless LAN. In
N
ETWORK
infrastructure mode, the wireless devices communicate with each other
and to a wired network by first going through an access point. An
infrastructure wireless network connected to a wired network is referred to
as a Basic Service Set (BSS). A set of two or more BSS in a single network
is referred to as an Extended Service Set (ESS). Infrastructure mode is
useful at a corporation scale, or when it is necessary to connect the wired
and wireless networks.
Spread Spectrum technology is a wideband radio frequency technique
S
S
PREAD
PECTRUM
developed by the military for use in reliable, secure, mission-critical
communications 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).
A Service Set Identification is a thirty-two character (maximum)
SSID
alphanumeric key identifying a wireless local area network. For the wireless
devices in a network to communicate with each other, all devices must be
configured with the same SSID. This is typically the configuration
parameter for a wireless PC card. It corresponds to the ESSID in the
wireless access point and to the wireless network name. See also Wireless
Network Name and ESSID.
A data privacy mechanism based on a 64-bit, 128-bit, or 152-bit shared
WEP (W
IRED
key algorithm, as described in the IEEE 802.11 standard. To gain access to
E
P
)
QUIVALENT
RIVACY
a WEP network, you must know the key. The key is a string of characters
that you create. When using WEP, you must determine the level of
encryption. The type of encryption determines the key length; 128-bit
encryption requires a longer key than 64-bit encryption. Keys are defined
by entering a string in HEX (hexadecimal - using characters 0-9, A-F) or
ASCII (American Standard Code for Information Interchange –
alphanumeric characters) format. The ASCII format is provided so you can
enter a string that is easier to remember. The ASCII string is converted to
HEX for use over the network. Four keys can be defined so that you can
change keys easily.
A trade name for the 802.11b wireless networking standard, given by the
W
-F
I
I
Wireless Ethernet Compatibility Alliance (WECA, see http://www.wi-fi.net),
an industry standards group promoting interoperability among 802.11b
devices.
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G
LOSSARY
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