Wireless Local Area Networks (WLANs)
Wireless LANs, or WLANs, use radio frequency (RF)
technology to transmit and receive data over the air. This minimizes the need
for wired connections. WLANs give users mobility as they allow connection to a
local area network without having to be physically connected by a cable. This
freedom means users can access shared resources without looking for a place to
plug in cables, provided that their terminals are mobile and within the
designated network coverage area. With mobility, WLANs give flexibility and
increased productivity, appealing to both entrepreneurs and to home users.
WLANs may also enable network administrators to connect devices that may be
physically difficult to reach with a cable.
The Institute for Electrical and Electronic
Engineers (IEEE) developed the 802.11 specification for wireless LAN
technology. 802.11 specifies over-the-air interface between a wireless client
and a base station, or between two wireless clients. WLAN 802.11 standards also
have security protocols that were developed to provide the same level of
security as that of a wired LAN.
The first of these protocols is Wired Equivalent Privacy (WEP). WEP provides security by encrypting data sent over radio waves from end point to end point.
The first of these protocols is Wired Equivalent Privacy (WEP). WEP provides security by encrypting data sent over radio waves from end point to end point.
The second WLAN security protocol is Wi-Fi
Protected Access (WPA). WPA was developed as an upgrade to the security
features of WEP. It works with existing products that are WEP-enabled but
provides two key improvements: improved data encryption through the temporal
key integrity protocol (TKIP) which scrambles the keys using a hashing
algorithm. It has means for integrity-checking to ensure that keys have not
been tampered with. WPA also provides user authentication with the extensible
authentication protocol (EAP).
Wireless Protocols
|
Specification
|
Data Rate
|
Modulation Scheme
|
Security
|
|
802.11
|
1 or 2 Mbps in the 2.4 GHz band
|
FHSS, DSSS
|
WEP and WPA
|
|
802.11a
|
54 Mbps in the 5 GHz band
|
OFDM
|
WEP and WPA
|
|
802.11b/High Rate/Wi-Fi
|
11 Mbps (with a fallback to 5.5, 2, and 1 Mbps) in the 2.4 GHz band
|
DSSS with CCK
|
WEP and WPA
|
|
802.11g/Wi-Fi
|
54 Mbps in the 2.4 GHz band
|
OFDM when above 20Mbps, DSSS with CCK when below 20Mbps
|
WEP and WPA
|
More than just a technology, the Internet has
become a way of life for many people, and it has spurred a revolution of sorts
for both public and private sharing of information. The most popular source of
information about almost anything, the Internet is used daily by technical and
non-technical users alike.
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