User's Manual

Winmate Communication Inc. User Guide Feb 12, 2001
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Cyclic Redundancy Check (CRC)
An error-detection process that (at the transmitting station) divides the data being sent
by a particular polynomial and appends the resulting remainder to the transmitted
data.
Data link layer
The bottom second layer of the OSI layers. It provides synchronization and
transmission error control to packets. In 802.11 LANs, it encompasses the logical link
control (LLC) and medium access control (MAC) layers.
Differential quadrature phase shift keying (DQPSK)
A modulation process that the IEEE 802.11 direct sequence physical layer uses to
transmit data. It operates at a specific center frequency and varies the phase of the
signal to represent double-bit symbols.
Direct sequence spread spectrum (DSSS)
Combines a data signal at the sending station with a higher data rate bit sequence,
which many refer to as a chip sequence (aka. processing gain). A high processing gain
increases the signal’s resistance to interference.
Extended Service Set (ESS)
A collection of basic service sets tied together via a distribution system.
Frequency hopping spread spectrum (FHSS)
Takes the data signal and modulates it with a carrier signal that hops from frequency
to frequency as a function of time over a wide band of frequencies.
IEEE 802.X
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. The 802.11 committee
completed a standard for 1 and 2 Mbps wireless LANs in 1997 that has a single MAC
layer for the following physical-layer technologies: Frequency Hopping Spread
Spectrum, Direct Sequence Spread Spectrum, and Infrared. IEEE 802.11 b, an 11
Mbps version of the standard, was finalized at the end of 1999.
Independent Basic Service Set Network (IBSS Network)
A 802.11-based wireless network that has no backbone infrastructure and consists of