Wireless Local Area Networks

In 1997, the IEEE ratifi ed the 802.11 WLAN standards, establishing a global standard

for implementing and deploying WLANs. The throughput for 802.11 is 2 Mbps, which

was well below the IEEE 802.3 Ethernet counterpart. Late in 1999, the IEEE ratifi ed

the 802.11b standard extension, which raised the throughput to 11 Mbps, making this

extension more comparable to the wired equivalent. The 802.11b standard also supports

the 2-Mbps data rate and operates on the 2.4-GHz band in radio frequency for high-speed

data communications.

WLANs are typically found within a small client node-dense locale (e.g., a campus or

offi ce building), or anywhere a traditional network cannot be deployed for logistical

reasons. Benefi ts include user mobility in the coverage area, speed and simplicity of

physical setup, and scalability. Being a military spinoff, WLANs also provide security

features such as encryption, frequency hopping, and fi rewalls. Some of these features

are intrinsic to the protocol, making some aspects of WLANs at least as secure as

wired networks and usually more so. The drawbacks are high initial cost (mostly

hardware), limited range, possibility of mutual interference, and the need to securityenable

clients.