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Wireless Local Area Network (WLAN), also known as Wi-Fi (short for
Wireless fidelity) are shard by communications equipment following the
various versions of the IEEE 802.11 standard implemented at the 2.4Ghz
(unlicensed) frequency band uses Direct Sequence Spread Spectrum
(DSSS) to support data transfer at 1, 2, 5.5 and 11 Mbps. Such networks are providing wireless
connectivity for various computing devices such as laptop computers,
Personal Digital Assistants (PDA), digital camera, and even desktop
PCs equipped with a wireless network adapter. Future
JTRS radio will support waveforms to seamlessly connect with
802.11 standard devices.
Wi-Fi equipped devices can establish an ad-hoc network,
when grouped at close range or be served from a "hot-spot" service
point, located at a central area. Typical coverage of such access
point is 45 m (150 ft) indoors and 90 m (300 ft) outdoors.
To perform at higher data rates and at longer range, especially in
difficult terrain, systems use
dual diversity antennas (two or four antenna arrays) and radio amplifiers and directional
antennas, coverage can be extended to several kilometers, over line of
sight connections.
WLAN technologies are widely used for military
applications, primarily in
vehicular applications, command posts, ad-hoc networking for
special forces and small teams using "Personnel
Role radios" (PRR) . Future applications are currently evaluated,
including the use of Wi-Fi communications to communicate between team
members, deploying integrated
Infantry
Combat Suits. Other applications include the networking of
unattended ground sensors for surveillance, force protection and
intelligence gathering.
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