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WLAN Glossary
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Access Point
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A device that transports data between a wireless network and a wired network
(infrastructure).
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IEEE 802.X
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A set of specifications for Local Area Networks (LAN) from The Institute
of Electrical and Electronic Engineers (IEEE). Most wired networks conform
to 802.3, the specification for CSMA/CD based Ethernet networks or 802.5
the specification for token ring networks. There is an 802.11 committee working
on a standard for 1 and 2 Mbps wireless LANs. The standard will have a single
MAC layer for the following physical-layer technologies: Frequency Hopping
Spread Spectrum, Direct Sequence Spread Spectrum, and Infrared. Draft versions
of the specification are in process.
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Independent network
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A network that provides (usually temporarily) peer-to-peer connectivity without
relying on a complete network infrastructure.
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Infrastructure network
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A wireless network centered about an access point. In this environment, the
access point not only provides communication with the wired network but also
mediates wireless network traffic in the immediate neighborhood.
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Microcell
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A bounded physical space in which a number of wireless devices can communicate.
Because it is possible to have overlapping cells as well as isolated cells,
the boundaries of the cell are established by some rule or convention.
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Multipath
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The signal variation caused when radio signals take multiple paths from
transmitter to receiver.
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Radio Frequency (RF) Terms: GHz, MHz, Hz
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The international unit for measuring frequency is Hertz (Hz), which is equivalent
to the older unit of cycles per second. One Mega-Hertz (MHz) is one million
Hertz. One Giga-Hertz (GHz) is one billion Hertz. For reference: the standard
US electrical power frequency is 60 Hz, the AM broadcast radio frequency
band is 0.55 -1.6 MHz, the FM broadcast radio frequency band is 88-108 MHz,
and microwave ovens typically operate at 2.45 GHz.
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Roaming
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Movement of a wireless node between two microcells. Roaming usually occurs
in infrastructure networks built around multiple access points.
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Wireless Node
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A user computer with a wireless network interface card (adapter).
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